diff --git a/src/renderer/src/i18n/locales/zh-cn.json b/src/renderer/src/i18n/locales/zh-cn.json
index 30cc9b4315..6ef7f834b9 100644
--- a/src/renderer/src/i18n/locales/zh-cn.json
+++ b/src/renderer/src/i18n/locales/zh-cn.json
@@ -2916,7 +2916,7 @@
         "singleFileName": {
           "title": "自定义文件名（可选）",
           "placeholder": "如：cherry-studio.<hostname>.<device>.zip",
-          "help": "• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip\n• 支持的变量：{hostname} - 主机名，{device} - 设备类型\n• 不支持的字符：<>:\"/\\|?*\n• 最大长度：250个字符",
+          "help": "留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip\n支持的变量：{hostname} - 主机名，{device} - 设备类型\n不支持的字符：<>:\"/\\|?*\n最大长度：250个字符",
           "invalid_chars": "文件名包含无效字符",
           "reserved": "文件名是系统保留名称",
           "too_long": "文件名过长"
diff --git a/src/renderer/src/pages/settings/DataSettings/LocalBackupSettings.tsx b/src/renderer/src/pages/settings/DataSettings/LocalBackupSettings.tsx
index cb8c668e8a..5a74883c93 100644
--- a/src/renderer/src/pages/settings/DataSettings/LocalBackupSettings.tsx
+++ b/src/renderer/src/pages/settings/DataSettings/LocalBackupSettings.tsx
@@ -69,6 +69,11 @@ const LocalBackupSettings: React.FC = () => {
 
   const { localBackupSync } = useAppSelector((state) => state.backup)
 
+  // 同步 maxBackups 状态
+  useEffect(() => {
+    setMaxBackups(localBackupMaxBackupsSetting)
+  }, [localBackupMaxBackupsSetting])
+
   const onSyncIntervalChange = (value: number) => {
     setSyncInterval(value)
     dispatch(_setLocalBackupSyncInterval(value))
@@ -273,37 +278,6 @@ const LocalBackupSettings: React.FC = () => {
     <SettingGroup theme={theme}>
       <SettingTitle>{t('settings.data.local.title')}</SettingTitle>
       <SettingDivider />
-      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
-      <SettingRow>
-        <SettingRowTitle>
-          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
-        </SettingRowTitle>
-        <Switch
-          checked={localSingleFileOverwrite}
-          onChange={onSingleFileOverwriteChange}
-          disabled={!(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingRow>
-        <SettingHelpText>
-          {t('settings.data.backup.singleFileOverwrite.help') ||
-            '当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。'}
-        </SettingHelpText>
-      </SettingRow>
-      <SettingRow>
-        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
-        <Input
-          placeholder={
-            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
-          }
-          value={localSingleFileName}
-          onChange={(e) => onSingleFileNameChange(e.target.value)}
-          onBlur={onSingleFileNameBlur}
-          style={{ width: 300 }}
-          disabled={!localSingleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingDivider />
       <SettingRow>
         <SettingRowTitle>{t('settings.data.local.directory.label')}</SettingRowTitle>
         <HStack gap="5px">
@@ -383,6 +357,58 @@ const LocalBackupSettings: React.FC = () => {
       <SettingRow>
         <SettingHelpText>{t('settings.data.backup.skip_file_data_help')}</SettingHelpText>
       </SettingRow>
+      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>
+          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
+        </SettingRowTitle>
+        <Switch
+          checked={localSingleFileOverwrite}
+          onChange={onSingleFileOverwriteChange}
+          disabled={!(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileOverwrite.help') || (
+            <div>
+              <p>当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。</p>
+              <p style={{ marginTop: 8, fontSize: 12, color: 'var(--text-secondary)' }}>
+                推荐场景：只需要保留最新备份，节省本地存储空间
+              </p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
+        <Input
+          placeholder={
+            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
+          }
+          value={localSingleFileName}
+          onChange={(e) => onSingleFileNameChange(e.target.value)}
+          onBlur={onSingleFileNameBlur}
+          style={{ width: 300 }}
+          disabled={!localSingleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileName.help') || (
+            <div style={{ fontSize: 12, color: 'var(--text-secondary)' }}>
+              <p>• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip</p>
+              <p>
+                • 支持的变量：{`{hostname}`} - 主机名，{`{device}`} - 设备类型
+              </p>
+              <p>• 不支持的字符：{'<>:"/\\|?*'}</p>
+              <p>• 最大长度：250个字符</p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
       {localBackupSync && syncInterval > 0 && (
         <>
           <SettingDivider />
diff --git a/src/renderer/src/pages/settings/DataSettings/NutstoreSettings.tsx b/src/renderer/src/pages/settings/DataSettings/NutstoreSettings.tsx
index a5d2a7f77b..f539df9294 100644
--- a/src/renderer/src/pages/settings/DataSettings/NutstoreSettings.tsx
+++ b/src/renderer/src/pages/settings/DataSettings/NutstoreSettings.tsx
@@ -20,6 +20,8 @@ import {
   setNutstoreAutoSync,
   setNutstoreMaxBackups,
   setNutstorePath,
+  setNutstoreSingleFileName,
+  setNutstoreSingleFileOverwrite,
   setNutstoreSkipBackupFile,
   setNutstoreSyncInterval,
   setNutstoreToken
@@ -44,7 +46,9 @@ const NutstoreSettings: FC = () => {
     nutstoreAutoSync,
     nutstoreSyncState,
     nutstoreSkipBackupFile,
-    nutstoreMaxBackups
+    nutstoreMaxBackups,
+    nutstoreSingleFileOverwrite,
+    nutstoreSingleFileName
   } = useAppSelector((state) => state.nutstore)
 
   const dispatch = useAppDispatch()
@@ -55,12 +59,20 @@ const NutstoreSettings: FC = () => {
   const [checkConnectionLoading, setCheckConnectionLoading] = useState(false)
   const [nsConnected, setNsConnected] = useState<boolean>(false)
   const [syncInterval, setSyncInterval] = useState<number>(nutstoreSyncInterval)
+  const [maxBackups, setMaxBackups] = useState<number>(nutstoreMaxBackups)
   const [nutSkipBackupFile, setNutSkipBackupFile] = useState<boolean>(nutstoreSkipBackupFile)
+  const [nutSingleFileOverwrite, setNutSingleFileOverwrite] = useState<boolean>(nutstoreSingleFileOverwrite ?? false)
+  const [nutSingleFileName, setNutSingleFileName] = useState<string>(nutstoreSingleFileName ?? '')
   const [backupManagerVisible, setBackupManagerVisible] = useState(false)
 
   const nutstoreSSOHandler = useNutstoreSSO()
   const { setTimeoutTimer } = useTimer()
 
+  // 同步 maxBackups 状态
+  useEffect(() => {
+    setMaxBackups(nutstoreMaxBackups)
+  }, [nutstoreMaxBackups])
+
   const handleClickNutstoreSSO = useCallback(async () => {
     const ssoUrl = await window.api.nutstore.getSSOUrl()
     window.open(ssoUrl, '_blank')
@@ -142,9 +154,72 @@ const NutstoreSettings: FC = () => {
   }
 
   const onMaxBackupsChange = (value: number) => {
+    setMaxBackups(value)
     dispatch(setNutstoreMaxBackups(value))
   }
 
+  const onSingleFileOverwriteChange = (value: boolean) => {
+    // Only show confirmation when enabling
+    if (value && !nutSingleFileOverwrite) {
+      window.modal.confirm({
+        title: t('settings.data.backup.singleFileOverwrite.confirm.title') || '启用覆盖式备份',
+        content: (
+          <div>
+            <p>{t('settings.data.backup.singleFileOverwrite.confirm.content1') || '启用后，自动备份将：'}</p>
+            <ul style={{ marginLeft: 20, marginTop: 10 }}>
+              <li>{t('settings.data.backup.singleFileOverwrite.confirm.item1') || '使用固定文件名，不再添加时间戳'}</li>
+              <li>{t('settings.data.backup.singleFileOverwrite.confirm.item2') || '每次备份都会覆盖同名文件'}</li>
+              <li>{t('settings.data.backup.singleFileOverwrite.confirm.item3') || '仅保留最新的一个备份文件'}</li>
+            </ul>
+            <p style={{ marginTop: 10, color: 'var(--text-secondary)' }}>
+              {t('settings.data.backup.singleFileOverwrite.confirm.note') ||
+                '注意：此设置仅在自动备份且保留份数为1时生效'}
+            </p>
+          </div>
+        ),
+        okText: t('common.confirm') || '确认',
+        cancelText: t('common.cancel') || '取消',
+        onOk: () => {
+          setNutSingleFileOverwrite(value)
+          dispatch(setNutstoreSingleFileOverwrite(value))
+        }
+      })
+    } else {
+      setNutSingleFileOverwrite(value)
+      dispatch(setNutstoreSingleFileOverwrite(value))
+    }
+  }
+
+  const onSingleFileNameChange = (value: string) => {
+    setNutSingleFileName(value)
+  }
+
+  const onSingleFileNameBlur = () => {
+    const trimmed = nutSingleFileName.trim()
+    // Validate filename
+    if (trimmed) {
+      // Check for invalid characters
+      const invalidChars = /[<>:"/\\|?*]/
+      if (invalidChars.test(trimmed)) {
+        window.toast.error(t('settings.data.backup.singleFileName.invalid_chars') || '文件名包含无效字符')
+        return
+      }
+      // Check for reserved names (Windows)
+      const reservedNames = /^(CON|PRN|AUX|NUL|COM[1-9]|LPT[1-9])$/i
+      const nameWithoutExt = trimmed.replace(/\.zip$/i, '')
+      if (reservedNames.test(nameWithoutExt)) {
+        window.toast.error(t('settings.data.backup.singleFileName.reserved') || '文件名是系统保留名称')
+        return
+      }
+      // Check length
+      if (trimmed.length > 250) {
+        window.toast.error(t('settings.data.backup.singleFileName.too_long') || '文件名过长')
+        return
+      }
+    }
+    dispatch(setNutstoreSingleFileName(trimmed))
+  }
+
   const handleClickPathChange = async () => {
     if (!nutstoreToken) {
       return
@@ -336,6 +411,60 @@ const NutstoreSettings: FC = () => {
           <SettingRow>
             <SettingHelpText>{t('settings.data.backup.skip_file_data_help')}</SettingHelpText>
           </SettingRow>
+          {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
+          <SettingDivider />
+          <SettingRow>
+            <SettingRowTitle>
+              {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
+            </SettingRowTitle>
+            <Switch
+              checked={nutSingleFileOverwrite}
+              onChange={onSingleFileOverwriteChange}
+              disabled={!(syncInterval > 0 && maxBackups === 1)}
+            />
+          </SettingRow>
+          <SettingRow>
+            <SettingHelpText>
+              {t('settings.data.backup.singleFileOverwrite.help') || (
+                <div>
+                  <p>当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。</p>
+                  <p style={{ marginTop: 8, fontSize: 12, color: 'var(--text-secondary)' }}>
+                    推荐场景：只需要保留最新备份，节省坚果云存储空间
+                  </p>
+                </div>
+              )}
+            </SettingHelpText>
+          </SettingRow>
+          <SettingDivider />
+          <SettingRow>
+            <SettingRowTitle>
+              {t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}
+            </SettingRowTitle>
+            <Input
+              placeholder={
+                t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
+              }
+              value={nutSingleFileName}
+              onChange={(e) => onSingleFileNameChange(e.target.value)}
+              onBlur={onSingleFileNameBlur}
+              style={{ width: 300 }}
+              disabled={!nutSingleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
+            />
+          </SettingRow>
+          <SettingRow>
+            <SettingHelpText>
+              {t('settings.data.backup.singleFileName.help') || (
+                <div style={{ fontSize: 12, color: 'var(--text-secondary)' }}>
+                  <p>• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip</p>
+                  <p>
+                    • 支持的变量：{`{hostname}`} - 主机名，{`{device}`} - 设备类型
+                  </p>
+                  <p>• 不支持的字符：{'<>:"/\\|?*'}</p>
+                  <p>• 最大长度：250个字符</p>
+                </div>
+              )}
+            </SettingHelpText>
+          </SettingRow>
         </>
       )}
       <>
diff --git a/src/renderer/src/pages/settings/DataSettings/S3Settings.tsx b/src/renderer/src/pages/settings/DataSettings/S3Settings.tsx
index 38bc0b05c2..354ddfc7d5 100644
--- a/src/renderer/src/pages/settings/DataSettings/S3Settings.tsx
+++ b/src/renderer/src/pages/settings/DataSettings/S3Settings.tsx
@@ -13,7 +13,7 @@ import { setS3Partial } from '@renderer/store/settings'
 import { S3Config } from '@renderer/types'
 import { Button, Input, Switch, Tooltip } from 'antd'
 import dayjs from 'dayjs'
-import { FC, useState } from 'react'
+import { FC, useEffect, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 
 import { SettingDivider, SettingGroup, SettingHelpText, SettingRow, SettingRowTitle, SettingTitle } from '..'
@@ -56,6 +56,11 @@ const S3Settings: FC = () => {
 
   const { s3Sync } = useAppSelector((state) => state.backup)
 
+  // 同步 maxBackups 状态
+  useEffect(() => {
+    setMaxBackups(s3MaxBackupsInit)
+  }, [s3MaxBackupsInit])
+
   const onSyncIntervalChange = (value: number) => {
     setSyncInterval(value)
     dispatch(setS3Partial({ syncInterval: value, autoSync: value !== 0 }))
@@ -192,37 +197,6 @@ const S3Settings: FC = () => {
       </SettingTitle>
       <SettingHelpText>{t('settings.data.s3.title.help')}</SettingHelpText>
       <SettingDivider />
-      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
-      <SettingRow>
-        <SettingRowTitle>
-          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
-        </SettingRowTitle>
-        <Switch
-          checked={singleFileOverwrite}
-          onChange={onSingleFileOverwriteChange}
-          disabled={!(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingRow>
-        <SettingHelpText>
-          {t('settings.data.backup.singleFileOverwrite.help') ||
-            '当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。S3 会直接覆盖同键对象。'}
-        </SettingHelpText>
-      </SettingRow>
-      <SettingRow>
-        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
-        <Input
-          placeholder={
-            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
-          }
-          value={singleFileName}
-          onChange={(e) => onSingleFileNameChange(e.target.value)}
-          onBlur={onSingleFileNameBlur}
-          style={{ width: 300 }}
-          disabled={!singleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingDivider />
       <SettingRow>
         <SettingRowTitle>{t('settings.data.s3.endpoint.label')}</SettingRowTitle>
         <Input
@@ -357,6 +331,58 @@ const S3Settings: FC = () => {
       <SettingRow>
         <SettingHelpText>{t('settings.data.s3.skipBackupFile.help')}</SettingHelpText>
       </SettingRow>
+      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>
+          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
+        </SettingRowTitle>
+        <Switch
+          checked={singleFileOverwrite}
+          onChange={onSingleFileOverwriteChange}
+          disabled={!(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileOverwrite.help') || (
+            <div>
+              <p>当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。</p>
+              <p style={{ marginTop: 8, fontSize: 12, color: 'var(--text-secondary)' }}>
+                推荐场景：只需要保留最新备份，节省存储空间（S3会直接覆盖同键对象）
+              </p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
+        <Input
+          placeholder={
+            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
+          }
+          value={singleFileName}
+          onChange={(e) => onSingleFileNameChange(e.target.value)}
+          onBlur={onSingleFileNameBlur}
+          style={{ width: 300 }}
+          disabled={!singleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileName.help') || (
+            <div style={{ fontSize: 12, color: 'var(--text-secondary)' }}>
+              <p>• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip</p>
+              <p>
+                • 支持的变量：{`{hostname}`} - 主机名，{`{device}`} - 设备类型
+              </p>
+              <p>• 不支持的字符：{'<>:"/\\|?*'}</p>
+              <p>• 最大长度：250个字符</p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
       {syncInterval > 0 && (
         <>
           <SettingDivider />
diff --git a/src/renderer/src/pages/settings/DataSettings/WebDavSettings.tsx b/src/renderer/src/pages/settings/DataSettings/WebDavSettings.tsx
index 6e62662a36..86d02fe1a0 100644
--- a/src/renderer/src/pages/settings/DataSettings/WebDavSettings.tsx
+++ b/src/renderer/src/pages/settings/DataSettings/WebDavSettings.tsx
@@ -22,7 +22,7 @@ import {
 } from '@renderer/store/settings'
 import { Button, Input, Switch, Tooltip } from 'antd'
 import dayjs from 'dayjs'
-import { FC, useState } from 'react'
+import { FC, useEffect, useState } from 'react'
 import { useTranslation } from 'react-i18next'
 
 import { SettingDivider, SettingGroup, SettingHelpText, SettingRow, SettingRowTitle, SettingTitle } from '..'
@@ -63,6 +63,11 @@ const WebDavSettings: FC = () => {
 
   const { webdavSync } = useAppSelector((state) => state.backup)
 
+  // 同步 maxBackups 状态
+  useEffect(() => {
+    setMaxBackups(webDAVMaxBackups)
+  }, [webDAVMaxBackups])
+
   // 把之前备份的文件定时上传到 webdav，首先先配置 webdav 的 host, port, user, pass, path
 
   const onSyncIntervalChange = (value: number) => {
@@ -193,57 +198,6 @@ const WebDavSettings: FC = () => {
     <SettingGroup theme={theme}>
       <SettingTitle>{t('settings.data.webdav.title')}</SettingTitle>
       <SettingDivider />
-      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
-      <SettingRow>
-        <SettingRowTitle>
-          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
-        </SettingRowTitle>
-        <Switch
-          checked={webdavSingleFileOverwrite}
-          onChange={onSingleFileOverwriteChange}
-          disabled={!(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingRow>
-        <SettingHelpText>
-          {t('settings.data.backup.singleFileOverwrite.help') || (
-            <div>
-              <p>当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。</p>
-              <p style={{ marginTop: 8, fontSize: 12, color: 'var(--text-secondary)' }}>
-                推荐场景：只需要保留最新备份，节省存储空间
-              </p>
-            </div>
-          )}
-        </SettingHelpText>
-      </SettingRow>
-      <SettingRow>
-        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
-        <Input
-          placeholder={
-            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
-          }
-          value={webdavSingleFileName}
-          onChange={(e) => onSingleFileNameChange(e.target.value)}
-          onBlur={onSingleFileNameBlur}
-          style={{ width: 300 }}
-          disabled={!webdavSingleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
-        />
-      </SettingRow>
-      <SettingRow>
-        <SettingHelpText>
-          {t('settings.data.backup.singleFileName.help') || (
-            <div style={{ fontSize: 12, color: 'var(--text-secondary)' }}>
-              <p>• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip</p>
-              <p>
-                • 支持的变量：{`{hostname}`} - 主机名，{`{device}`} - 设备类型
-              </p>
-              <p>• 不支持的字符：{'<>:"/\\|?*'}</p>
-              <p>• 最大长度：250个字符</p>
-            </div>
-          )}
-        </SettingHelpText>
-      </SettingRow>
-      <SettingDivider />
       <SettingRow>
         <SettingRowTitle>{t('settings.data.webdav.host.label')}</SettingRowTitle>
         <Input
@@ -357,6 +311,58 @@ const WebDavSettings: FC = () => {
       <SettingRow>
         <SettingHelpText>{t('settings.data.webdav.disableStream.help')}</SettingHelpText>
       </SettingRow>
+      {/* 覆盖式单文件备份，仅在自动备份开启且保留份数=1时推荐启用 */}
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>
+          {t('settings.data.backup.singleFileOverwrite.title') || '覆盖式单文件备份（同名覆盖）'}
+        </SettingRowTitle>
+        <Switch
+          checked={webdavSingleFileOverwrite}
+          onChange={onSingleFileOverwriteChange}
+          disabled={!(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileOverwrite.help') || (
+            <div>
+              <p>当自动备份开启且保留份数为1时，使用固定文件名每次覆盖。</p>
+              <p style={{ marginTop: 8, fontSize: 12, color: 'var(--text-secondary)' }}>
+                推荐场景：只需要保留最新备份，节省存储空间
+              </p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
+      <SettingDivider />
+      <SettingRow>
+        <SettingRowTitle>{t('settings.data.backup.singleFileName.title') || '自定义文件名（可选）'}</SettingRowTitle>
+        <Input
+          placeholder={
+            t('settings.data.backup.singleFileName.placeholder') || '如：cherry-studio.<hostname>.<device>.zip'
+          }
+          value={webdavSingleFileName}
+          onChange={(e) => onSingleFileNameChange(e.target.value)}
+          onBlur={onSingleFileNameBlur}
+          style={{ width: 300 }}
+          disabled={!webdavSingleFileOverwrite || !(syncInterval > 0 && maxBackups === 1)}
+        />
+      </SettingRow>
+      <SettingRow>
+        <SettingHelpText>
+          {t('settings.data.backup.singleFileName.help') || (
+            <div style={{ fontSize: 12, color: 'var(--text-secondary)' }}>
+              <p>• 留空将使用默认格式：cherry-studio.[主机名].[设备类型].zip</p>
+              <p>
+                • 支持的变量：{`{hostname}`} - 主机名，{`{device}`} - 设备类型
+              </p>
+              <p>• 不支持的字符：{'<>:"/\\|?*'}</p>
+              <p>• 最大长度：250个字符</p>
+            </div>
+          )}
+        </SettingHelpText>
+      </SettingRow>
       {webdavSync && syncInterval > 0 && (
         <>
           <SettingDivider />
diff --git a/src/renderer/src/services/NutstoreService.ts b/src/renderer/src/services/NutstoreService.ts
index 17dee74708..ab28d9ab75 100644
--- a/src/renderer/src/services/NutstoreService.ts
+++ b/src/renderer/src/services/NutstoreService.ts
@@ -7,6 +7,7 @@ import { NUTSTORE_HOST } from '@shared/config/nutstore'
 import dayjs from 'dayjs'
 import { type CreateDirectoryOptions } from 'webdav'
 
+import { shouldSkipCleanup, validateAndSanitizeFilename } from '../utils/backupUtils'
 import { getBackupData, handleData } from './BackupService'
 
 const logger = loggerService.withContext('NutstoreService')
@@ -109,10 +110,12 @@ async function cleanupOldBackups(webdavConfig: WebDavConfig, maxBackups: number)
 
 export async function backupToNutstore({
   showMessage = false,
-  customFileName = ''
+  customFileName = '',
+  isAutoBackup = false
 }: {
   showMessage?: boolean
   customFileName?: string
+  isAutoBackup?: boolean
 } = {}) {
   const nutstoreToken = getNutstoreToken()
   if (!nutstoreToken) {
@@ -135,21 +138,37 @@ export async function backupToNutstore({
   } catch (error) {
     logger.error('[backupToNutstore] Failed to get device type:', error as Error)
   }
-  const timestamp = dayjs().format('YYYYMMDDHHmmss')
-  const backupFileName = customFileName || `cherry-studio.${timestamp}.${deviceType}.zip`
-  const finalFileName = backupFileName.endsWith('.zip') ? backupFileName : `${backupFileName}.zip`
+
+  const backupData = await getBackupData()
+  const skipBackupFile = store.getState().nutstore.nutstoreSkipBackupFile
+  const maxBackups = store.getState().nutstore.nutstoreMaxBackups
+  const singleFileOverwrite = store.getState().nutstore.nutstoreSingleFileOverwrite
+  const singleFileName = store.getState().nutstore.nutstoreSingleFileName
+
+  // Handle filename generation
+  let finalFileName: string
+  if (isAutoBackup && singleFileOverwrite && maxBackups === 1) {
+    // Use overwrite logic for auto backup when single file overwrite is enabled
+    const hostname = await window.api.system.getHostname()
+    const name = await validateAndSanitizeFilename(singleFileName, hostname, deviceType)
+    finalFileName = name
+  } else {
+    // Use timestamped logic for manual backup or when overwrite is disabled
+    const timestamp = dayjs().format('YYYYMMDDHHmmss')
+    const name = customFileName || `cherry-studio.${timestamp}.${deviceType}.zip`
+    finalFileName = name.endsWith('.zip') ? name : `${name}.zip`
+  }
 
   isManualBackupRunning = true
 
   store.dispatch(setNutstoreSyncState({ syncing: true, lastSyncError: null }))
 
-  const backupData = await getBackupData()
-  const skipBackupFile = store.getState().nutstore.nutstoreSkipBackupFile
-  const maxBackups = store.getState().nutstore.nutstoreMaxBackups
-
   try {
-    // 先清理旧备份
-    await cleanupOldBackups(config, maxBackups)
+    // Skip cleanup for single file overwrite mode when maxBackups is 1
+    if (!shouldSkipCleanup(maxBackups, singleFileOverwrite)) {
+      // 先清理旧备份
+      await cleanupOldBackups(config, maxBackups)
+    }
 
     const isSuccess = await window.api.backup.backupToWebdav(backupData, {
       ...config,
@@ -264,7 +283,7 @@ export async function startNutstoreAutoSync() {
     isAutoBackupRunning = true
     try {
       logger.verbose('[Nutstore AutoSync] Starting auto backup...')
-      await backupToNutstore({ showMessage: false })
+      await backupToNutstore({ showMessage: false, isAutoBackup: true })
     } catch (error) {
       logger.error('[Nutstore AutoSync] Auto backup failed:', error as Error)
     } finally {
diff --git a/src/renderer/src/store/nutstore.ts b/src/renderer/src/store/nutstore.ts
index e2a05f021e..558282a745 100644
--- a/src/renderer/src/store/nutstore.ts
+++ b/src/renderer/src/store/nutstore.ts
@@ -12,6 +12,8 @@ export interface NutstoreState {
   nutstoreSyncState: NutstoreSyncState
   nutstoreSkipBackupFile: boolean
   nutstoreMaxBackups: number
+  nutstoreSingleFileOverwrite: boolean
+  nutstoreSingleFileName: string
 }
 
 const initialState: NutstoreState = {
@@ -25,7 +27,9 @@ const initialState: NutstoreState = {
     lastSyncError: null
   },
   nutstoreSkipBackupFile: false,
-  nutstoreMaxBackups: 0
+  nutstoreMaxBackups: 0,
+  nutstoreSingleFileOverwrite: false,
+  nutstoreSingleFileName: ''
 }
 
 const nutstoreSlice = createSlice({
@@ -52,6 +56,12 @@ const nutstoreSlice = createSlice({
     },
     setNutstoreMaxBackups: (state, action: PayloadAction<number>) => {
       state.nutstoreMaxBackups = action.payload
+    },
+    setNutstoreSingleFileOverwrite: (state, action: PayloadAction<boolean>) => {
+      state.nutstoreSingleFileOverwrite = action.payload
+    },
+    setNutstoreSingleFileName: (state, action: PayloadAction<string>) => {
+      state.nutstoreSingleFileName = action.payload
     }
   }
 })
@@ -63,7 +73,9 @@ export const {
   setNutstoreSyncInterval,
   setNutstoreSyncState,
   setNutstoreSkipBackupFile,
-  setNutstoreMaxBackups
+  setNutstoreMaxBackups,
+  setNutstoreSingleFileOverwrite,
+  setNutstoreSingleFileName
 } = nutstoreSlice.actions
 
 export default nutstoreSlice.reducer