diff --git a/apps/api/app/tasks/lipsync_tts.py b/apps/api/app/tasks/lipsync_tts.py
index 6c9fa417e..85a478828 100644
--- a/apps/api/app/tasks/lipsync_tts.py
+++ b/apps/api/app/tasks/lipsync_tts.py
@@ -9,18 +9,52 @@
 5. 签名 URL 并提交到 MediaKit
 6. 更新 job 状态为 submitted
 7. 异常时标记 job 为 failed
+
+注意：使用 @shared_task 而非绑定到某个 celery_app 实例，
+确保任务能被 Worker 侧 celery_app 正确注册，同时 API 侧 send_task/apply_async 仍可正常调用。
 """
 
 import io
 import logging
 from datetime import datetime, timezone
+from urllib.parse import urlparse
 
-from app.core.celery_app import celery_app
+from celery import shared_task
 
 logger = logging.getLogger(__name__)
 
+# MediaKit 预签名 URL 有效期（7天，秒），与 LipsyncService._sign_media_url 保持一致
+_MEDIAKIT_URL_TTL_SECONDS = 7 * 24 * 3600
 
-@celery_app.task(
+
+def _sign_media_url(url: str) -> str:
+    """对自家 OSS 私有桶 URL 重签长有效期预签名.
+
+    - 自家 OSS URL → 重签 7 天有效期
+    - 外部临时 URL → 原样透传
+    - 任何异常降级原样返回，不阻断主流程
+    """
+    if not url:
+        return url
+    try:
+        from packages.shared.storage import get_shared_storage_service
+
+        storage = get_shared_storage_service()
+        public_base = getattr(storage, "public_url", "")
+        if not isinstance(public_base, str) or not public_base:
+            return url
+        own_host = urlparse(public_base).netloc.lower()
+        host = urlparse(url).netloc.lower()
+        if not own_host or host != own_host:
+            return url
+        signed = storage.get_download_url(url, expires_seconds=_MEDIAKIT_URL_TTL_SECONDS)
+        return signed or url
+    except Exception as exc:  # noqa: BLE001
+        logger.warning("[lipsync_tts] URL 重签失败，原样返回: url_prefix=%s err=%s", url[:80], exc)
+        return url
+
+
+@shared_task(
     bind=True,
     name="lipsync_tts.synthesize_and_submit",
     max_retries=2,
@@ -45,7 +79,6 @@ def tts_synthesize_and_submit(
     from packages.adapters.sqlalchemy_impl.database import SessionLocal
     from packages.adapters.sqlalchemy_impl.models import LipsyncJobModel
     from packages.application.cosyvoice_service import CosyVoiceError, CosyVoiceService
-    from packages.shared.storage import get_shared_storage_service
     from packages.shared.url_security import safe_download_bytes
 
     db: DBSession = SessionLocal()
@@ -109,26 +142,35 @@ def tts_synthesize_and_submit(
             audio_data = safe_download_bytes(
                 temp_url,
                 purpose="lipsync_tts_audio",
-                allowed_mime_types=("audio/mpeg", "audio/mp3", "audio/wav", "audio/mp4", "audio/x-m4a"),
+                allowed_mime_types=(
+                    "audio/mpeg",
+                    "audio/mp3",
+                    "audio/wav",
+                    "audio/mp4",
+                    "audio/x-m4a",
+                ),
                 timeout=60.0,
             )
+            from packages.shared.storage import get_shared_storage_service
+
             storage = get_shared_storage_service()
             storage_key = f"lipsync-tts/{user_id}/{job_id}.mp3"
             permanent_url = storage.upload_file(io.BytesIO(audio_data), storage_key, content_type="audio/mpeg")
             logger.info("[lipsync_tts] TTS 音频已转存 OSS: job_id=%s key=%s", job_id, storage_key)
             job.audio_url = permanent_url
         except Exception as exc:
-            logger.warning("[lipsync_tts] TTS 音频转存 OSS 失败，回退临时 URL: job_id=%s err=%s", job_id, exc)
+            logger.warning(
+                "[lipsync_tts] TTS 音频转存 OSS 失败，回退临时 URL: job_id=%s err=%s",
+                job_id,
+                exc,
+            )
             job.audio_url = temp_url
 
         db.commit()
 
-        # 3. 签名 URL 并提交到 MediaKit
-        from app.services.lipsync_service import LipsyncService
-
-        temp_service = LipsyncService.__new__(LipsyncService)
-        audio_url = temp_service._sign_media_url(job.audio_url)
-        video_url = temp_service._sign_media_url(job.video_url)
+        # 3. 签名 URL 并提交到 MediaKit（复用模块内 _sign_media_url，避免对 LipsyncService 的耦合）
+        audio_url = _sign_media_url(job.audio_url)
+        video_url = _sign_media_url(job.video_url)
 
         client = get_mediakit_client()
         try:
@@ -141,7 +183,11 @@ def tts_synthesize_and_submit(
             job.mediakit_task_id = mk_result["task_id"]
             job.status = "submitted"
             job.submitted_at = datetime.now(timezone.utc)
-            logger.info("[lipsync_tts] 已提交 MediaKit: job_id=%s task_id=%s", job_id, mk_result["task_id"])
+            logger.info(
+                "[lipsync_tts] 已提交 MediaKit: job_id=%s task_id=%s",
+                job_id,
+                mk_result["task_id"],
+            )
         except MediaKitError as exc:
             job.status = "failed"
             job.error_message = str(exc)
diff --git a/apps/web/src/pages/ai-avatar/api/aiAvatar.ts b/apps/web/src/pages/ai-avatar/api/aiAvatar.ts
index d4d8e379b..13b9acf1b 100644
--- a/apps/web/src/pages/ai-avatar/api/aiAvatar.ts
+++ b/apps/web/src/pages/ai-avatar/api/aiAvatar.ts
@@ -54,7 +54,7 @@ export const createLipsyncJob = async (data: {
 }
 
 export const getLipsyncJob = async (id: string): Promise<LipsyncJob> => {
-  const response = await apiClient.get<LipsyncJob>(`/lipsync/jobs/${id}`)
+  const response = await apiClient.get<LipsyncJob>(`/lipsync/jobs/${id}`, { timeout: 60000 })
   return response.data
 }
 
diff --git a/tests/unit/test_lipsync_speed_optimization.py b/tests/unit/test_lipsync_speed_optimization.py
index 67752d1c7..9adfd44d4 100644
--- a/tests/unit/test_lipsync_speed_optimization.py
+++ b/tests/unit/test_lipsync_speed_optimization.py
@@ -358,7 +358,7 @@ def _apply_all_patches(
     patches = [
         patch.dict(sys.modules, {"packages.adapters.sqlalchemy_impl.database": fake_db_mod}),
         patch(
-            "app.services.lipsync_service.LipsyncService._sign_media_url",
+            "app.tasks.lipsync_tts._sign_media_url",
             side_effect=lambda url: url + "?signed" if url else url,
         ),
     ]
@@ -598,7 +598,7 @@ class TestTtsSynthesizeAndSubmit:
         all_patches = [
             patch.dict(sys.modules, {"packages.adapters.sqlalchemy_impl.database": fake_db_mod}),
             patch(
-                "app.services.lipsync_service.LipsyncService._sign_media_url",
+                "app.tasks.lipsync_tts._sign_media_url",
                 side_effect=lambda url: url + "?signed" if url else url,
             ),
             patch(