diff --git a/src/renderer/src/pages/home/Messages/MessageGroup.tsx b/src/renderer/src/pages/home/Messages/MessageGroup.tsx
index 8b4c35e103..0f5a7e83f7 100644
--- a/src/renderer/src/pages/home/Messages/MessageGroup.tsx
+++ b/src/renderer/src/pages/home/Messages/MessageGroup.tsx
@@ -11,7 +11,7 @@ import type { Topic } from '@renderer/types'
 import type { Message } from '@renderer/types/newMessage'
 import { classNames } from '@renderer/utils'
 import { Popover } from 'antd'
-import { memo, useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { ComponentProps, memo, useCallback, useEffect, useMemo, useState } from 'react'
 import styled from 'styled-components'
 
 import { useChatMaxWidth } from '../Chat'
@@ -43,9 +43,6 @@ const MessageGroup = ({ messages, topic, registerMessageElement }: Props) => {
   )
   const [selectedIndex, setSelectedIndex] = useState(messageLength - 1)
 
-  // Refs
-  const prevMessageLengthRef = useRef(messageLength)
-
   // 对于单模型消息，采用简单的样式，避免 overflow 影响内部的 sticky 效果
   const multiModelMessageStyle = useMemo(
     () => (messageLength < 2 ? 'fold' : _multiModelMessageStyle),
@@ -83,24 +80,6 @@ const MessageGroup = ({ messages, topic, registerMessageElement }: Props) => {
     },
     [editMessage, selectedMessageId, setTimeoutTimer]
   )
-
-  useEffect(() => {
-    if (messageLength > prevMessageLengthRef.current) {
-      setSelectedIndex(messageLength - 1)
-      const lastMessage = messages[messageLength - 1]
-      if (lastMessage) {
-        setSelectedMessage(lastMessage)
-      }
-    } else {
-      const newIndex = messages.findIndex((msg) => msg.id === selectedMessageId)
-      if (newIndex !== -1) {
-        setSelectedIndex(newIndex)
-      }
-    }
-    prevMessageLengthRef.current = messageLength
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [messageLength])
-
   // 添加对流程图节点点击事件的监听
   useEffect(() => {
     // 只在组件挂载和消息数组变化时添加监听器
@@ -223,7 +202,7 @@ const MessageGroup = ({ messages, topic, registerMessageElement }: Props) => {
         message,
         topic,
         index: message.index
-      }
+      } satisfies ComponentProps<typeof MessageItem>
 
       const messageContent = (
         <MessageWrapper
@@ -277,7 +256,7 @@ const MessageGroup = ({ messages, topic, registerMessageElement }: Props) => {
       isGrouped,
       topic,
       multiModelMessageStyle,
-      messages.length,
+      messages,
       selectedMessageId,
       onUpdateUseful,
       groupContextMessageId,
diff --git a/src/renderer/src/store/thunk/messageThunk.ts b/src/renderer/src/store/thunk/messageThunk.ts
index 665127e603..c9b33eea8e 100644
--- a/src/renderer/src/store/thunk/messageThunk.ts
+++ b/src/renderer/src/store/thunk/messageThunk.ts
@@ -1446,7 +1446,7 @@ export const appendAssistantResponseThunk =
       }
 
       // 2. Create the new assistant message stub
-      const newAssistantStub = createAssistantMessage(assistant.id, topicId, {
+      const newAssistantMessageStub = createAssistantMessage(assistant.id, topicId, {
         askId: askId, // Crucial: Use the original askId
         model: newModel,
         modelId: newModel.id,
@@ -1459,9 +1459,14 @@ export const appendAssistantResponseThunk =
       const insertAtIndex = existingMessageIndex !== -1 ? existingMessageIndex + 1 : currentTopicMessageIds.length
 
       // 4. Update Database (Save the stub to the topic's message list)
-      await saveMessageAndBlocksToDB(newAssistantStub, [], insertAtIndex)
+      await saveMessageAndBlocksToDB(newAssistantMessageStub, [], insertAtIndex)
 
-      dispatch(newMessagesActions.insertMessageAtIndex({ topicId, message: newAssistantStub, index: insertAtIndex }))
+      dispatch(
+        newMessagesActions.insertMessageAtIndex({ topicId, message: newAssistantMessageStub, index: insertAtIndex })
+      )
+
+      dispatch(updateMessageAndBlocksThunk(topicId, { id: existingAssistantMessageId, foldSelected: false }, []))
+      dispatch(updateMessageAndBlocksThunk(topicId, { id: newAssistantMessageStub.id, foldSelected: true }, []))
 
       // 5. Prepare and queue the processing task
       const assistantConfigForThisCall = {
@@ -1475,7 +1480,7 @@ export const appendAssistantResponseThunk =
           getState,
           topicId,
           assistantConfigForThisCall,
-          newAssistantStub // Pass the newly created stub
+          newAssistantMessageStub // Pass the newly created stub
         )
       })
     } catch (error) {