diff --git a/src/main/java/com/genersoft/iot/vmp/aiot/service/impl/AiScreenshotServiceImpl.java b/src/main/java/com/genersoft/iot/vmp/aiot/service/impl/AiScreenshotServiceImpl.java
index 42e2cd489..8de97a5a7 100644
--- a/src/main/java/com/genersoft/iot/vmp/aiot/service/impl/AiScreenshotServiceImpl.java
+++ b/src/main/java/com/genersoft/iot/vmp/aiot/service/impl/AiScreenshotServiceImpl.java
@@ -156,9 +156,12 @@ public class AiScreenshotServiceImpl implements IAiScreenshotService {
                     JSONObject res = JSON.parseObject(resultJson);
                     result.put("status", res.getString("status"));
                     if ("ok".equals(res.getString("status"))) {
-                        result.put("url", res.getString("url"));
+                        String url = res.getString("url");
+                        result.put("url", url);
                         // 降级成功，写入缓存
-                        writeCache(cameraCode, res.getString("url"));
+                        writeCache(cameraCode, url);
+                        // 降级路径也要持久化 cos_key 到 DB，否则后续 proxyImage 会找不到记录
+                        persistCosKey(cameraCode, url, requestId);
                     } else {
                         result.put("message", res.getString("message"));
                     }
@@ -209,26 +212,7 @@ public class AiScreenshotServiceImpl implements IAiScreenshotService {
         if ("ok".equals(status) && cameraCode != null) {
             String url = (String) data.get("url");
             writeCache(cameraCode, url);
-
-            // 从URL解析cos_key（优先），失败时降级使用pendingCosKeys
-            String cosKey = extractCosKeyFromUrl(url);
-            if (cosKey == null) {
-                cosKey = pendingCosKeys.remove(requestId);
-            } else {
-                // 解析成功，也要清理pendingCosKeys避免内存泄漏
-                pendingCosKeys.remove(requestId);
-            }
-
-            if (cosKey != null) {
-                try {
-                    snapshotMapper.upsert(cameraCode, cosKey);
-                    log.info("[AI截图] cos_key 已持久化: cameraCode={}, cosKey={}", cameraCode, cosKey);
-                } catch (Exception e) {
-                    log.error("[AI截图] 持久化 cos_key 失败: cameraCode={}, error={}", cameraCode, e.getMessage());
-                }
-            } else {
-                log.warn("[AI截图] 无法获取cos_key: cameraCode={}, url={}", cameraCode, url);
-            }
+            persistCosKey(cameraCode, url, requestId);
         } else {
             pendingCosKeys.remove(requestId);
         }
@@ -284,6 +268,30 @@ public class AiScreenshotServiceImpl implements IAiScreenshotService {
         return null;
     }
 
+    /**
+     * 持久化 cos_key 到 DB（从 URL 解析或从 pendingCosKeys 获取）
+     * 供降级路径和回调路径共用
+     */
+    private void persistCosKey(String cameraCode, String url, String requestId) {
+        String cosKey = extractCosKeyFromUrl(url);
+        if (cosKey == null) {
+            cosKey = pendingCosKeys.remove(requestId);
+        } else {
+            pendingCosKeys.remove(requestId);
+        }
+
+        if (cosKey != null) {
+            try {
+                snapshotMapper.upsert(cameraCode, cosKey);
+                log.info("[AI截图] cos_key 已持久化(降级路径): cameraCode={}, cosKey={}", cameraCode, cosKey);
+            } catch (Exception e) {
+                log.error("[AI截图] 持久化 cos_key 失败(降级路径): cameraCode={}, error={}", cameraCode, e.getMessage());
+            }
+        } else {
+            log.warn("[AI截图] 降级路径无法获取cos_key: cameraCode={}, url={}", cameraCode, url);
+        }
+    }
+
     /**
      * 写入截图缓存
      */