diff --git a/backend/src/main/java/com/designhub/service/ExternalAssetService.java b/backend/src/main/java/com/designhub/service/ExternalAssetService.java
index 7827c35..36ed532 100644
--- a/backend/src/main/java/com/designhub/service/ExternalAssetService.java
+++ b/backend/src/main/java/com/designhub/service/ExternalAssetService.java
@@ -130,13 +130,16 @@ public class ExternalAssetService {
         String apiKey = systemConfigService.getConfigValue("external_asset_api_key");
         
         if (apiUrl == null || apiUrl.isEmpty() || apiKey == null || apiKey.isEmpty()) {
+            log.warn("第三方素材API配置不完整");
             return false;
         }
         
         try {
-            // 测试连接（使用一个测试任务号）
+            // 测试连接（使用正确格式的测试任务号）
             String url = apiUrl.endsWith("/") ? apiUrl : apiUrl + "/";
-            url = url + "product-assets?taskNo=TEST000000000000";
+            url = url + "product-assets?taskNo=TASK000000000000";
+            
+            log.info("测试第三方素材API连接: {}", url);
             
             HttpHeaders headers = new HttpHeaders();
             headers.set("X-API-Key", apiKey);
@@ -150,12 +153,42 @@ public class ExternalAssetService {
                 String.class
             );
             
+            log.info("测试连接响应状态: {}", response.getStatusCode());
+            
             // 只要能收到响应（无论是404还是200），说明连接正常
             return response.getStatusCode().is2xxSuccessful() || 
                    response.getStatusCode() == HttpStatus.NOT_FOUND;
                    
+        } catch (org.springframework.web.client.HttpClientErrorException e) {
+            // HTTP 4xx 错误
+            log.info("测试连接HTTP错误: {} - {}", e.getStatusCode(), e.getResponseBodyAsString());
+            
+            // 400 Bad Request 但是包含业务错误码（如TASK_NOT_FOUND, INVALID_TASK_NO）
+            // 说明API连接正常，只是参数不对
+            if (e.getStatusCode() == HttpStatus.BAD_REQUEST) {
+                String body = e.getResponseBodyAsString();
+                if (body.contains("TASK_NOT_FOUND") || body.contains("INVALID_TASK_NO")) {
+                    log.info("API连接正常，测试任务号不存在或格式不对（这是正常的）");
+                    return true;
+                }
+            }
+            
+            // 404 Not Found 也说明连接正常
+            if (e.getStatusCode() == HttpStatus.NOT_FOUND) {
+                log.info("API连接正常，任务不存在（这是正常的）");
+                return true;
+            }
+            
+            // 401/403 认证错误
+            if (e.getStatusCode() == HttpStatus.UNAUTHORIZED || 
+                e.getStatusCode() == HttpStatus.FORBIDDEN) {
+                log.error("API密钥无效或权限不足");
+                return false;
+            }
+            
+            return false;
         } catch (Exception e) {
-            log.error("测试第三方素材API连接失败", e);
+            log.error("测试第三方素材API连接失败: {}", e.getMessage());
             return false;
         }
     }