diff --git a/graph/llms/openai_compat_backend.py b/graph/llms/openai_compat_backend.py
index 3e590d5..17300e0 100644
--- a/graph/llms/openai_compat_backend.py
+++ b/graph/llms/openai_compat_backend.py
@@ -593,7 +593,14 @@ class OpenAICompatBackend(LLMBackend):
             print(f"[pinterest_analyze] 解析失败: {e}")
             return []
         designs = []
-        for i, d in enumerate(parsed.get("designs") or []):
+        # 兼容 LLM 返回裸数组（[...]）或 {designs: [...]} 两种结构
+        if isinstance(parsed, dict):
+            designs_raw = parsed.get("designs") or []
+        elif isinstance(parsed, list):
+            designs_raw = parsed
+        else:
+            designs_raw = []
+        for i, d in enumerate(designs_raw):
             if not isinstance(d, dict):
                 continue
             designs.append({
diff --git a/graph/nodes/pinterest_analyze_node.py b/graph/nodes/pinterest_analyze_node.py
index 4e3c05a..0740d0f 100644
--- a/graph/nodes/pinterest_analyze_node.py
+++ b/graph/nodes/pinterest_analyze_node.py
@@ -104,13 +104,15 @@ def pinterest_analyze_node(state: Dict[str, Any]) -> Dict[str, Any]:
                                "message": f"term[{term}]: {e}", "trace": ""})
                 print(f"[pinterest_analyze] 「{term}」分析失败: {e}")
 
-    # 3) 兜底：LLM 无结果 → mock 规则简报（零 API 成本，保证有设计可生成）
-    if not raw_briefs and llm is not None:
+    # 3) 兜底：LLM 无结果 → mock 规则简报（零 API 成本，保证有设计可生成）。
+    #    注意必须切到 mock 后端，不能再调回失败的 llm（否则同样报错）。
+    if not raw_briefs:
         try:
+            mock = get_backend("mock")
             for term, paths in images.items():
                 sample = list(paths)[:analyze_per_term]
                 if sample:
-                    raw_briefs.extend(llm.analyze_pinterest_images(sample, term, country) or [])
+                    raw_briefs.extend(mock.analyze_pinterest_images(sample, term, country) or [])
             print(f"[pinterest_analyze] 兜底：mock 规则简报 {len(raw_briefs)} 条")
         except Exception as e:  # noqa: BLE001
             print(f"[pinterest_analyze] mock 兜底失败: {e}")