diff --git a/app/ui/streamlit_app.py b/app/ui/streamlit_app.py
index 8ada8ad..874a133 100644
--- a/app/ui/streamlit_app.py
+++ b/app/ui/streamlit_app.py
@@ -914,9 +914,14 @@ def render_backtest() -> None:
                                             "保存这些权重为默认配置",
                                             key="save_decision_env_weights_single",
                                         ):
-                                            cfg.agent_weights.update_from_dict(weights_dict)
-                                            save_config(cfg)
-                                            st.success("代理权重已写入 config.json")
+                                            try:
+                                                cfg.agent_weights.update_from_dict(weights_dict)
+                                                save_config(cfg)
+                                            except Exception as exc:  # noqa: BLE001
+                                                LOGGER.exception("保存权重失败", extra={**LOG_EXTRA, "error": str(exc)})
+                                                st.error(f"写入配置失败：{exc}")
+                                            else:
+                                                st.success("代理权重已写入 config.json")
 
                                     nav_series = info.get("nav_series")
                                     if nav_series:
@@ -1085,11 +1090,16 @@ def render_backtest() -> None:
                                             "保存所选权重为默认配置",
                                             key="save_decision_env_weights_batch",
                                         ):
-                                            cfg.agent_weights.update_from_dict(selected_row.get("权重", {}))
-                                            save_config(cfg)
-                                            st.success(
-                                                f"已将序号 {selected_row['序号']} 的权重写入 config.json"
-                                            )
+                                            try:
+                                                cfg.agent_weights.update_from_dict(selected_row.get("权重", {}))
+                                                save_config(cfg)
+                                            except Exception as exc:  # noqa: BLE001
+                                                LOGGER.exception("批量保存权重失败", extra={**LOG_EXTRA, "error": str(exc)})
+                                                st.error(f"写入配置失败：{exc}")
+                                            else:
+                                                st.success(
+                                                    f"已将序号 {selected_row['序号']} 的权重写入 config.json"
+                                                )
                                     else:
                                         st.caption("暂无成功的结果可供保存。")
 
diff --git a/app/utils/config.py b/app/utils/config.py
index 653cc14..8204eff 100644
--- a/app/utils/config.py
+++ b/app/utils/config.py
@@ -3,11 +3,15 @@ from __future__ import annotations
 
 from dataclasses import dataclass, field
 import json
+import logging
 import os
 from pathlib import Path
 from typing import Dict, Iterable, List, Mapping, Optional
 
 
+LOGGER = logging.getLogger(__name__)
+
+
 def _default_root() -> Path:
     return Path(__file__).resolve().parents[2] / "app" / "data"
 
@@ -26,7 +30,13 @@ class DataPaths:
         self.database = self.root / "llm_quant.db"
         self.backups = self.root / "backups"
         self.backups.mkdir(parents=True, exist_ok=True)
-        self.config_file = self.root / "config.json"
+        config_override = os.getenv("LLM_QUANT_CONFIG_PATH")
+        if config_override:
+            config_path = Path(config_override).expanduser()
+            config_path.parent.mkdir(parents=True, exist_ok=True)
+        else:
+            config_path = self.root / "config.json"
+        self.config_file = config_path
 
 
 @dataclass
@@ -38,6 +48,7 @@ class AgentWeights:
     news: float = 0.20
     liquidity: float = 0.15
     macro: float = 0.15
+    risk: float = 1.0
 
     def as_dict(self) -> Dict[str, float]:
         return {
@@ -46,6 +57,7 @@ class AgentWeights:
             "A_news": self.news,
             "A_liq": self.liquidity,
             "A_macro": self.macro,
+            "A_risk": self.risk,
         }
 
     def update_from_dict(self, data: Mapping[str, float]) -> None:
@@ -60,6 +72,8 @@ class AgentWeights:
             "liquidity": "liquidity",
             "A_macro": "macro",
             "macro": "macro",
+            "A_risk": "risk",
+            "risk": "risk",
         }
         for key, attr in mapping.items():
             if key in data and data[key] is not None:
@@ -581,12 +595,25 @@ def save_config(cfg: AppConfig | None = None) -> None:
             for code, dept in cfg.departments.items()
         },
     }
+    serialized = json.dumps(payload, ensure_ascii=False, indent=2)
+
+    try:
+        existing = path.read_text(encoding="utf-8")
+    except OSError:
+        existing = None
+
+    if existing == serialized:
+        LOGGER.info("配置未变更，跳过写入：%s", path)
+        return
+
     try:
         path.parent.mkdir(parents=True, exist_ok=True)
-        with path.open("w", encoding="utf-8") as fh:
-            json.dump(payload, fh, ensure_ascii=False, indent=2)
+        tmp_path = path.with_suffix(path.suffix + ".tmp") if path.suffix else path.with_name(path.name + ".tmp")
+        tmp_path.write_text(serialized, encoding="utf-8")
+        tmp_path.replace(path)
+        LOGGER.info("配置已写入：%s", path)
     except OSError:
-        pass
+        LOGGER.exception("配置写入失败：%s", path)
 
 
 def _load_env_defaults(cfg: AppConfig) -> None: