diff --git a/frontend/src/features/chats/composables/useChatUnreadCount.ts b/frontend/src/features/chats/composables/useChatUnreadCount.ts
index fb5fa11..fa4c8d1 100644
--- a/frontend/src/features/chats/composables/useChatUnreadCount.ts
+++ b/frontend/src/features/chats/composables/useChatUnreadCount.ts
@@ -4,6 +4,9 @@ import type { RouteLocationNormalizedLoaded } from 'vue-router'
 import { fetchUnreadChatCount } from '@/features/chats/api/chats'
 import { useSessionStore } from '@/stores/session'
 
+const pollingInterval = 300_000
+const unreadChangedEvent = 'chat-unread-changed'
+
 export function useChatUnreadCount(route: RouteLocationNormalizedLoaded) {
   const session = useSessionStore()
   const unreadCount = ref(0)
@@ -32,14 +35,19 @@ export function useChatUnreadCount(route: RouteLocationNormalizedLoaded) {
         unreadCount.value = count
       }
     } catch {
-      // 底部导航不弹错误提示，保持上一次未读数即可。
+      // 不弹错误提示，保持上一次未读数即可。
     }
   }
 
+  function onUnreadChanged() {
+    void loadUnreadCount()
+  }
+
   function startPolling() {
     stopPolling()
     void loadUnreadCount()
-    timer = window.setInterval(loadUnreadCount, 30_000)
+    timer = window.setInterval(loadUnreadCount, pollingInterval)
+    window.addEventListener(unreadChangedEvent, onUnreadChanged)
   }
 
   onMounted(() => {
@@ -48,7 +56,10 @@ export function useChatUnreadCount(route: RouteLocationNormalizedLoaded) {
     }
   })
 
-  onBeforeUnmount(stopPolling)
+  onBeforeUnmount(() => {
+    stopPolling()
+    window.removeEventListener(unreadChangedEvent, onUnreadChanged)
+  })
 
   watch(
     () => session.isLoggedIn,
@@ -58,6 +69,7 @@ export function useChatUnreadCount(route: RouteLocationNormalizedLoaded) {
         return
       }
       stopPolling()
+      window.removeEventListener(unreadChangedEvent, onUnreadChanged)
       unreadCount.value = 0
     }
   )
diff --git a/frontend/src/features/chats/views/ChatView.vue b/frontend/src/features/chats/views/ChatView.vue
index 3f3e46a..f795876 100644
--- a/frontend/src/features/chats/views/ChatView.vue
+++ b/frontend/src/features/chats/views/ChatView.vue
@@ -48,6 +48,7 @@ const desktopNotification = useDesktopNotification('user')
 
 function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'new_message') {
+    window.dispatchEvent(new Event('chat-unread-changed'))
     const msg = event.message
     if (msg) {
       const isSelf = msg.sender_type === 'user' && msg.sender_id === currentUserId
diff --git a/frontend/src/features/chats/views/MessagesView.vue b/frontend/src/features/chats/views/MessagesView.vue
index a7479a4..9f0aa6f 100644
--- a/frontend/src/features/chats/views/MessagesView.vue
+++ b/frontend/src/features/chats/views/MessagesView.vue
@@ -81,6 +81,7 @@ async function loadChats(isRefresh = false, showLoading = true) {
 function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'new_message' || event.type === 'conversation_updated') {
     loadChats(true, false)
+    window.dispatchEvent(new Event('chat-unread-changed'))
   }
   if (event.type === 'new_message' && event.message) {
     const isSelf = event.message.sender_type === 'user' && event.message.sender_id === currentUserId
diff --git a/frontend/src/features/chats/views/MobileChatView.vue b/frontend/src/features/chats/views/MobileChatView.vue
index 8bb5854..038358c 100644
--- a/frontend/src/features/chats/views/MobileChatView.vue
+++ b/frontend/src/features/chats/views/MobileChatView.vue
@@ -44,6 +44,7 @@ const desktopNotification = useDesktopNotification('user')
 
 function handleSSEEvent(event: ChatEvent) {
   if (event.type === 'new_message') {
+    window.dispatchEvent(new Event('chat-unread-changed'))
     const msg = event.message
     if (msg) {
       const isSelf = msg.sender_type === 'user' && msg.sender_id === currentUserId