diff --git a/frontend/src/pages/meeting/preview.vue b/frontend/src/pages/meeting/preview.vue
index fe5df29..28adae7 100644
--- a/frontend/src/pages/meeting/preview.vue
+++ b/frontend/src/pages/meeting/preview.vue
@@ -16,7 +16,15 @@
 -->
 <template>
   <view v-if="initializing || autoJoin" class="auto-join-page">
-    <text class="auto-join-title">正在进入会议…</text>
+    <template v-if="autoJoinError">
+      <text class="auto-join-error-title">进入会议失败</text>
+      <text class="auto-join-error-msg">{{ autoJoinError }}</text>
+      <view class="auto-join-actions">
+        <button class="aj-btn aj-btn-primary" @click="retryAutoJoin">重试</button>
+        <button class="aj-btn aj-btn-secondary" @click="exitAutoJoin">返回</button>
+      </view>
+    </template>
+    <text v-else class="auto-join-title">正在进入会议…</text>
   </view>
   <view v-else class="page">
     <view class="container">
@@ -116,6 +124,9 @@ const joinCode = ref('')
 const joinPassword = ref('')
 const autoJoin = ref(false)
 const initializing = ref(true)
+// autoJoin 失败/超时的可见错误（替代无限"正在进入会议…"转圈）
+const autoJoinError = ref('')
+let autoJoinWatchdog = null
 
 const modeLabel = computed(() => mode.value === 'create' ? '即将创建新会议' : `即将加入会议 ${joinCode.value}`)
 
@@ -363,6 +374,42 @@ const onCancel = () => {
   uni.navigateBack()
 }
 
+// autoJoin 看门狗：若 15s 内既没进房也没报错（多见于 WS 连不上 / mediasoup 传输 ICE 不通而无限等待），
+// 主动把无限转圈切换成可见的超时错误，便于真机定位与重试。
+const startAutoJoinWatchdog = () => {
+  clearAutoJoinWatchdog()
+  autoJoinWatchdog = setTimeout(() => {
+    if (joining.value && !autoJoinError.value) {
+      autoJoinError.value = '连接会议服务器超时（15s）。可能是网络受限或会议服务（WebSocket/媒体通道）暂不可达，请重试或检查网络。'
+    }
+  }, 15000)
+}
+const clearAutoJoinWatchdog = () => {
+  if (autoJoinWatchdog) { clearTimeout(autoJoinWatchdog); autoJoinWatchdog = null }
+}
+
+const retryAutoJoin = () => {
+  autoJoinError.value = ''
+  joining.value = false
+  startAutoJoinWatchdog()
+  onJoin({ skipMedia: true })
+}
+
+const exitAutoJoin = () => {
+  clearAutoJoinWatchdog()
+  // 云律小程序 web-view 内：返回到小程序；否则回上一步
+  try {
+    const embedded = typeof window !== 'undefined' && window.sessionStorage
+      && window.sessionStorage.getItem('echo_cloud_law_meeting_embed') === '1'
+    const mp = typeof window !== 'undefined' && window.wx && window.wx.miniProgram ? window.wx.miniProgram : null
+    if (embedded && mp && typeof mp.navigateBack === 'function') {
+      mp.navigateBack({ delta: 1 })
+      return
+    }
+  } catch (e) {}
+  onCancel()
+}
+
 const onJoin = async (options = {}) => {
   if (joining.value || !canJoin.value) return
   joining.value = true
@@ -423,12 +470,17 @@ const onJoin = async (options = {}) => {
     uni.redirectTo({ url: `/pages/meeting/room${roomCode ? `?code=${roomCode}` : ''}` })
   } catch (err) {
     const msg = err?.message || JSON.stringify(err)
+    // autoJoin 模式下把错误显式呈现在页面（toast 一闪而过，真机很难看清）
+    if (autoJoin.value) {
+      autoJoinError.value = `加入失败：${msg}`
+    }
     uni.showToast({ title: `加入失败：${msg}`, icon: 'none', duration: 3500 })
     console.error('[Preview] 加入会议失败', err)
     // 入会失败：track 尚未转给 mediasoup 或刚拿到就失败，显式 stop 避免摄像头泄漏
     try { audioTrack && audioTrack.stop && audioTrack.stop() } catch {}
     try { videoTrack && videoTrack.stop && videoTrack.stop() } catch {}
   } finally {
+    clearAutoJoinWatchdog()
     joining.value = false
   }
 }
@@ -466,6 +518,7 @@ onLoad(async (query) => {
         hasPermission: hasPermission.value,
         permissionError: permissionError.value
       })
+      startAutoJoinWatchdog()
       onJoin({ skipMedia: true })
       return
     }
@@ -489,6 +542,7 @@ onBeforeUnmount(() => {
     clearTimeout(changeDebounceTimer)
     changeDebounceTimer = null
   }
+  clearAutoJoinWatchdog()
   stopPreviewStream()
   stopAudioMeter()
 })
@@ -499,13 +553,50 @@ onBeforeUnmount(() => {
   min-height: 100vh;
   background: #F8FAFC;
   display: flex;
+  flex-direction: column;
   align-items: center;
   justify-content: center;
+  padding: 0 48rpx;
 }
 .auto-join-title {
   font-size: 30rpx;
   color: #475569;
 }
+.auto-join-error-title {
+  font-size: 34rpx;
+  font-weight: 600;
+  color: #DC2626;
+  margin-bottom: 20rpx;
+}
+.auto-join-error-msg {
+  font-size: 26rpx;
+  line-height: 40rpx;
+  color: #475569;
+  text-align: center;
+  margin-bottom: 40rpx;
+  word-break: break-all;
+}
+.auto-join-actions {
+  display: flex;
+  gap: 24rpx;
+}
+.aj-btn {
+  min-width: 200rpx;
+  height: 80rpx;
+  line-height: 80rpx;
+  border-radius: 16rpx;
+  font-size: 28rpx;
+  text-align: center;
+  border: none;
+}
+.aj-btn-primary {
+  background: #3B82F6;
+  color: #FFFFFF;
+}
+.aj-btn-secondary {
+  background: #E2E8F0;
+  color: #334155;
+}
 .page { min-height: 100vh; background: #F8FAFC; padding: 24rpx; }
 .container { max-width: 960rpx; margin: 0 auto; }
 .title { font-size: 40rpx; font-weight: 600; color: #0F172A; display: block; margin: 24rpx 0 8rpx; }