diff --git a/packages/shared/gpu_encoder.py b/packages/shared/gpu_encoder.py
index c217b92cf..37d3cf0c3 100644
--- a/packages/shared/gpu_encoder.py
+++ b/packages/shared/gpu_encoder.py
@@ -323,6 +323,7 @@ class GpuEncoderClient:
             raise GpuEncodeError("GPU_ENCODE_RELAY_SECRET not set")
         return secret
 
+
     def _warm_up_if_needed(self) -> None:
         """POST 前预热：如果距上次成功通信超过 idle 阈值，先打 /health 打通 Tailscale 链路。
 
@@ -372,11 +373,13 @@ class GpuEncoderClient:
             first_byte_ok = True
             logger.debug(
                 "[gpu-encoder] P4000 first byte in %.2fs (connect_timeout=%.1fs)",
-                time.time() - t0,
-                connect_timeout,
+                time.time() - t0, connect_timeout,
             )
-            # 剩余用长超时
-            resp.fp._sock.settimeout(ffmpeg_timeout + 60)
+            # 剩余用长超时（给底层socket放宽时限；如果是mock/不支持，则跳过）
+            try:
+                resp.fp._sock.settimeout(ffmpeg_timeout + 60)
+            except (AttributeError, OSError):
+                pass
             rest = resp.read()
             raw = (first_chunk + rest).decode("utf-8")
             resp.close()
@@ -387,8 +390,10 @@ class GpuEncoderClient:
         except (urllib.error.URLError, socket.timeout, TimeoutError, ConnectionError, OSError) as e:
             waited = time.time() - t0
             hint = "first-byte" if not first_byte_ok else "ffmpeg/upload"
+            # 统一以 "connection error" 开头，便于上层 fallback 逻辑用关键词识别；
+            # 末尾再附带具体错误（timed out / refused ...）供排障
             raise GpuEncodeError(
-                f"P4000 {hint} timeout after {waited:.1f}s "
+                f"P4000 {hint} connection error after {waited:.1f}s "
                 f"(connect_timeout={connect_timeout:.0f}s, ffmpeg_timeout={ffmpeg_timeout}s): {e}"
             ) from e
         finally: