diff --git a/apps/api/src/core/config.py b/apps/api/src/core/config.py
index 1a8f18af..dc73049b 100644
--- a/apps/api/src/core/config.py
+++ b/apps/api/src/core/config.py
@@ -214,7 +214,26 @@ class Settings(BaseSettings):
     @field_validator("AI_FALLBACK_ORDER", mode="before")
     @classmethod
     def parse_ai_fallback(cls, v: str | list[str]) -> list[str]:
+        """
+        解析 AI_FALLBACK_ORDER，支援三種格式:
+        1. JSON: '["gemini","ollama","claude"]'
+        2. CSV:  'gemini,ollama,claude'
+        3. List: ["gemini", "ollama", "claude"]
+
+        2026-03-27 修復: ConfigMap 用 JSON 格式，原本只支援 CSV
+        """
+        import json
+
         if isinstance(v, str):
+            v = v.strip()
+            # 嘗試 JSON 解析 (ConfigMap 格式)
+            if v.startswith("["):
+                try:
+                    parsed = json.loads(v)
+                    return [p.strip().lower() for p in parsed]
+                except json.JSONDecodeError:
+                    pass  # 降級到 CSV 解析
+            # CSV 格式
             return [provider.strip().lower() for provider in v.split(",")]
         return [p.lower() for p in v]