diff --git a/src/renderer/src/pages/home/Chat.tsx b/src/renderer/src/pages/home/Chat.tsx
index 7846a1a7..d44b53c6 100644
--- a/src/renderer/src/pages/home/Chat.tsx
+++ b/src/renderer/src/pages/home/Chat.tsx
@@ -56,6 +56,8 @@ const Container = styled.div`
 
 const Main = styled(Flex)`
   height: calc(100vh - var(--navbar-height));
+  // 设置为containing block，方便子元素fixed定位
+  transform: translateZ(0);
 `
 
 export default Chat
diff --git a/src/renderer/src/pages/home/Messages/ChatNavigation.tsx b/src/renderer/src/pages/home/Messages/ChatNavigation.tsx
index 3f9c0c96..68f07402 100644
--- a/src/renderer/src/pages/home/Messages/ChatNavigation.tsx
+++ b/src/renderer/src/pages/home/Messages/ChatNavigation.tsx
@@ -24,7 +24,6 @@ const ChatNavigation: FC<ChatNavigationProps> = ({ containerId }) => {
   const lastMoveTime = useRef(0)
   const { topicPosition, showTopics } = useSettings()
   const showRightTopics = topicPosition === 'right' && showTopics
-  const right = showRightTopics ? 'calc(var(--topic-list-width) + 16px)' : '16px'
 
   // Reset hide timer and make buttons visible
   const resetHideTimer = useCallback(() => {
@@ -263,24 +262,11 @@ const ChatNavigation: FC<ChatNavigationProps> = ({ containerId }) => {
         clearTimeout(hideTimer)
       }
     }
-  }, [
-    containerId,
-    hideTimer,
-    resetHideTimer,
-    isNearButtons,
-    handleMouseEnter,
-    handleMouseLeave,
-    right,
-    showRightTopics
-  ])
+  }, [containerId, hideTimer, resetHideTimer, isNearButtons, handleMouseEnter, handleMouseLeave, showRightTopics])
 
   return (
     <>
-      <NavigationContainer
-        $isVisible={isVisible}
-        $right={right}
-        onMouseEnter={handleMouseEnter}
-        onMouseLeave={handleMouseLeave}>
+      <NavigationContainer $isVisible={isVisible} onMouseEnter={handleMouseEnter} onMouseLeave={handleMouseLeave}>
         <ButtonGroup>
           <Tooltip title={t('chat.navigation.prev')} placement="left">
             <NavigationButton
@@ -332,12 +318,11 @@ const ChatNavigation: FC<ChatNavigationProps> = ({ containerId }) => {
 
 interface NavigationContainerProps {
   $isVisible: boolean
-  $right: string
 }
 
 const NavigationContainer = styled.div<NavigationContainerProps>`
   position: fixed;
-  right: ${(props) => props.$right};
+  right: 16px;
   top: 50%;
   transform: translateY(-50%) translateX(${(props) => (props.$isVisible ? 0 : '100%')});
   z-index: 999;
diff --git a/src/renderer/src/pages/home/Messages/MessageAnchorLine.tsx b/src/renderer/src/pages/home/Messages/MessageAnchorLine.tsx
index be70d8f4..85ae773f 100644
--- a/src/renderer/src/pages/home/Messages/MessageAnchorLine.tsx
+++ b/src/renderer/src/pages/home/Messages/MessageAnchorLine.tsx
@@ -33,9 +33,6 @@ const MessageAnchorLine: FC<MessageLineProps> = ({ messages }) => {
   const messageItemsRef = useRef<Map<string, HTMLDivElement>>(new Map())
   const containerRef = useRef<HTMLDivElement>(null)
   const [mouseY, setMouseY] = useState<number | null>(null)
-  const { topicPosition, showTopics } = useSettings()
-  const showRightTopics = topicPosition === 'right' && showTopics
-  const right = showRightTopics ? 'calc(var(--topic-list-width) + 15px)' : '15px'
 
   const [listOffsetY, setListOffsetY] = useState(0)
   const [containerHeight, setContainerHeight] = useState<number | null>(null)
@@ -160,7 +157,6 @@ const MessageAnchorLine: FC<MessageLineProps> = ({ messages }) => {
       ref={containerRef}
       onMouseMove={handleMouseMove}
       onMouseLeave={handleMouseLeave}
-      $right={right}
       $height={containerHeight}>
       <MessagesList ref={messagesListRef} style={{ transform: `translateY(${listOffsetY}px)` }}>
         {messages.map((message, index) => {
@@ -226,11 +222,11 @@ const MessageItemContainer = styled.div`
   transform-origin: right center;
 `
 
-const MessageLineContainer = styled.div<{ $right: string; $height: number | null }>`
+const MessageLineContainer = styled.div<{ $height: number | null }>`
   width: 14px;
   position: fixed;
   top: ${(props) => (props.$height ? `calc(${props.$height / 2}px + var(--status-bar-height))` : '50%')};
-  right: ${(props) => props.$right};
+  right: 13px;
   max-height: ${(props) => (props.$height ? `${props.$height}px` : 'calc(100% - var(--status-bar-height) * 2)')};
   transform: translateY(-50%);
   z-index: 0;
diff --git a/src/renderer/src/pages/home/Messages/MessageGroup.tsx b/src/renderer/src/pages/home/Messages/MessageGroup.tsx
index b62f6f50..6719ef28 100644
--- a/src/renderer/src/pages/home/Messages/MessageGroup.tsx
+++ b/src/renderer/src/pages/home/Messages/MessageGroup.tsx
@@ -6,7 +6,7 @@ import { MultiModelMessageStyle } from '@renderer/store/settings'
 import type { Message, Topic } from '@renderer/types'
 import { classNames } from '@renderer/utils'
 import { Popover } from 'antd'
-import { memo, useCallback, useEffect, useState } from 'react'
+import { memo, useCallback, useEffect, useRef, useState } from 'react'
 import styled, { css } from 'styled-components'
 
 import MessageGroupMenuBar from './MessageGroupMenuBar'
@@ -27,14 +27,53 @@ const MessageGroup = ({ messages, topic, hidePresetMessages }: Props) => {
   )
 
   const messageLength = messages.length
+  const prevMessageLengthRef = useRef(messageLength)
   const [selectedIndex, setSelectedIndex] = useState(messageLength - 1)
 
+  const getSelectedMessageId = useCallback(() => {
+    const selectedMessage = messages.find((message) => message.foldSelected)
+    if (selectedMessage) {
+      return selectedMessage.id
+    }
+    return messages[0]?.id
+  }, [messages])
+
+  const setSelectedMessage = useCallback(
+    (message: Message) => {
+      messages.forEach(async (m) => {
+        await editMessage(m.id, { foldSelected: m.id === message.id })
+      })
+
+      setTimeout(() => {
+        const messageElement = document.getElementById(`message-${message.id}`)
+        if (messageElement) {
+          messageElement.scrollIntoView({ behavior: 'smooth', block: 'start' })
+        }
+      }, 200)
+    },
+    [editMessage, messages]
+  )
+
   const isGrouped = messageLength > 1 && messages.every((m) => m.role === 'assistant')
   const isHorizontal = multiModelMessageStyle === 'horizontal'
   const isGrid = multiModelMessageStyle === 'grid'
 
   useEffect(() => {
-    setSelectedIndex(messageLength - 1)
+    if (messageLength > prevMessageLengthRef.current) {
+      setSelectedIndex(messageLength - 1)
+      const lastMessage = messages[messageLength - 1]
+      if (lastMessage) {
+        setSelectedMessage(lastMessage)
+      }
+    } else {
+      const selectedId = getSelectedMessageId()
+      const newIndex = messages.findIndex((msg) => msg.id === selectedId)
+      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
@@ -70,22 +109,6 @@ const MessageGroup = ({ messages, topic, hidePresetMessages }: Props) => {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [messages, selectedIndex, isGrouped, messageLength])
 
-  const setSelectedMessage = useCallback(
-    (message: Message) => {
-      messages.forEach(async (m) => {
-        await editMessage(m.id, { foldSelected: m.id === message.id })
-      })
-
-      setTimeout(() => {
-        const messageElement = document.getElementById(`message-${message.id}`)
-        if (messageElement) {
-          messageElement.scrollIntoView({ behavior: 'smooth', block: 'start' })
-        }
-      }, 200)
-    },
-    [editMessage, messages]
-  )
-
   // 添加对LOCATE_MESSAGE事件的监听
   useEffect(() => {
     // 为每个消息注册一个定位事件监听器
@@ -146,7 +169,7 @@ const MessageGroup = ({ messages, topic, hidePresetMessages }: Props) => {
           className={classNames({
             'group-message-wrapper': message.role === 'assistant' && isHorizontal && isGrouped,
             [multiModelMessageStyle]: isGrouped,
-            selected: 'foldSelected' in message ? message.foldSelected : index === 0
+            selected: message.id === getSelectedMessageId()
           })}>
           <MessageStream {...messageProps} />
         </MessageWrapper>
@@ -183,7 +206,8 @@ const MessageGroup = ({ messages, topic, hidePresetMessages }: Props) => {
       selectedIndex,
       topic,
       hidePresetMessages,
-      gridPopoverTrigger
+      gridPopoverTrigger,
+      getSelectedMessageId
     ]
   )
 
@@ -210,6 +234,7 @@ const MessageGroup = ({ messages, topic, hidePresetMessages }: Props) => {
             })
           }}
           messages={messages}
+          selectMessageId={getSelectedMessageId()}
           setSelectedMessage={setSelectedMessage}
           topic={topic}
         />
diff --git a/src/renderer/src/pages/home/Messages/MessageGroupMenuBar.tsx b/src/renderer/src/pages/home/Messages/MessageGroupMenuBar.tsx
index 0dceb3ad..c8471efd 100644
--- a/src/renderer/src/pages/home/Messages/MessageGroupMenuBar.tsx
+++ b/src/renderer/src/pages/home/Messages/MessageGroupMenuBar.tsx
@@ -21,6 +21,7 @@ interface Props {
   multiModelMessageStyle: MultiModelMessageStyle
   setMultiModelMessageStyle: (style: MultiModelMessageStyle) => void
   messages: Message[]
+  selectMessageId: string
   setSelectedMessage: (message: Message) => void
   topic: Topic
 }
@@ -29,6 +30,7 @@ const MessageGroupMenuBar: FC<Props> = ({
   multiModelMessageStyle,
   setMultiModelMessageStyle,
   messages,
+  selectMessageId,
   setSelectedMessage,
   topic
 }) => {
@@ -75,7 +77,11 @@ const MessageGroupMenuBar: FC<Props> = ({
           ))}
         </LayoutContainer>
         {multiModelMessageStyle === 'fold' && (
-          <MessageGroupModelList messages={messages} setSelectedMessage={setSelectedMessage} />
+          <MessageGroupModelList
+            messages={messages}
+            selectMessageId={selectMessageId}
+            setSelectedMessage={setSelectedMessage}
+          />
         )}
         {multiModelMessageStyle === 'grid' && <MessageGroupSettings />}
       </HStack>
diff --git a/src/renderer/src/pages/home/Messages/MessageGroupModelList.tsx b/src/renderer/src/pages/home/Messages/MessageGroupModelList.tsx
index 695d3a05..9045beca 100644
--- a/src/renderer/src/pages/home/Messages/MessageGroupModelList.tsx
+++ b/src/renderer/src/pages/home/Messages/MessageGroupModelList.tsx
@@ -12,12 +12,13 @@ import styled from 'styled-components'
 
 interface MessageGroupModelListProps {
   messages: Message[]
+  selectMessageId: string
   setSelectedMessage: (message: Message) => void
 }
 
 type DisplayMode = 'compact' | 'expanded'
 
-const MessageGroupModelList: FC<MessageGroupModelListProps> = ({ messages, setSelectedMessage }) => {
+const MessageGroupModelList: FC<MessageGroupModelListProps> = ({ messages, selectMessageId, setSelectedMessage }) => {
   const dispatch = useAppDispatch()
   const { t } = useTranslation()
   const { foldDisplayMode } = useSettings()
@@ -47,7 +48,7 @@ const MessageGroupModelList: FC<MessageGroupModelListProps> = ({ messages, setSe
               <Tooltip key={index} title={message.model?.name} placement="top" mouseEnterDelay={0.2}>
                 <AvatarWrapper
                   className="avatar-wrapper"
-                  isSelected={'foldSelected' in message ? message.foldSelected! : index === 0}
+                  isSelected={message.id === selectMessageId}
                   onClick={() => {
                     setSelectedMessage(message)
                   }}>
@@ -59,7 +60,7 @@ const MessageGroupModelList: FC<MessageGroupModelListProps> = ({ messages, setSe
         ) : (
           /* Expanded style display */
           <Segmented
-            value={messages.find((message) => message.foldSelected)?.id || messages[0].id}
+            value={selectMessageId}
             onChange={(value) => {
               const message = messages.find((message) => message.id === value) as Message
               setSelectedMessage(message)
diff --git a/src/renderer/src/store/messages.ts b/src/renderer/src/store/messages.ts
index 510d409e..6e244b89 100644
--- a/src/renderer/src/store/messages.ts
+++ b/src/renderer/src/store/messages.ts
@@ -278,7 +278,6 @@ export const sendMessage =
           const assistantMessage = getAssistantMessage({ assistant, topic })
           assistantMessage.askId = userMessage.id
           assistantMessage.status = 'sending'
-          assistantMessage.foldSelected = true
           assistantMessages.push(assistantMessage)
         }