diff --git a/backend/scripts/run_parallel_simulation.py b/backend/scripts/run_parallel_simulation.py
index 38b211e..e9bb943 100644
--- a/backend/scripts/run_parallel_simulation.py
+++ b/backend/scripts/run_parallel_simulation.py
@@ -1019,25 +1019,24 @@ def create_model(config: Dict[str, Any], use_boost: bool = False):
     if not llm_model:
         llm_model = config.get("llm_model", "gpt-4o-mini")
     
-    # 设置 camel-ai 所需的环境变量
-    if llm_api_key:
-        os.environ["OPENAI_API_KEY"] = llm_api_key
-    
-    if not os.environ.get("OPENAI_API_KEY"):
-        raise ValueError("缺少 API Key 配置，请在项目根目录 .env 文件中设置 LLM_API_KEY")
-    
-    if llm_base_url:
-        os.environ["OPENAI_BASE_URL"] = llm_base_url
+    if not llm_api_key:
+        raise ValueError("LLM_API_KEY not configured. Set it in .env file.")
     
     print(f"{config_label} model={llm_model}, base_url={llm_base_url[:40] if llm_base_url else '默认'}...")
     
     # camel-ai reads OPENAI_API_KEY from env automatically
-    # For base_url, we must also set it as env var
-    # (model_config_dict passes values to create() call, not client constructor)
+    # Pass api_key and base_url via model_config_dict
+    # camel-ai extracts these for the OpenAI client constructor
+    model_config = {}
+    if llm_api_key:
+        model_config["api_key"] = llm_api_key
+    if llm_base_url:
+        model_config["base_url"] = llm_base_url
     
     return ModelFactory.create(
         model_platform=ModelPlatformType.OPENAI,
         model_type=llm_model,
+        model_config_dict=model_config,
     )
 
 
diff --git a/backend/scripts/run_reddit_simulation.py b/backend/scripts/run_reddit_simulation.py
index 1ae3687..fdd73cb 100644
--- a/backend/scripts/run_reddit_simulation.py
+++ b/backend/scripts/run_reddit_simulation.py
@@ -449,23 +449,23 @@ class RedditSimulationRunner:
         if not llm_model:
             llm_model = self.config.get("llm_model", "gpt-4o-mini")
         
-        # 设置 camel-ai 所需的环境变量
-        if llm_api_key:
-            os.environ["OPENAI_API_KEY"] = llm_api_key
-        
-        if not os.environ.get("OPENAI_API_KEY"):
-            raise ValueError("缺少 API Key 配置，请在项目根目录 .env 文件中设置 LLM_API_KEY")
-        
-        if llm_base_url:
-            os.environ["OPENAI_BASE_URL"] = llm_base_url
+        if not llm_api_key:
+            raise ValueError("LLM_API_KEY not configured. Set it in .env file.")
         
         print(f"LLM配置: model={llm_model}, base_url={llm_base_url[:40] if llm_base_url else '默认'}...")
         
-        # camel-ai reads OPENAI_API_KEY from env automatically
+        # Pass api_key and base_url via model_config_dict
+        # camel-ai extracts these for the OpenAI client constructor
+        model_config = {}
+        if llm_api_key:
+            model_config["api_key"] = llm_api_key
+        if llm_base_url:
+            model_config["base_url"] = llm_base_url
         
         return ModelFactory.create(
             model_platform=ModelPlatformType.OPENAI,
             model_type=llm_model,
+            model_config_dict=model_config,
         )
     
     def _get_active_agents_for_round(
diff --git a/backend/scripts/run_twitter_simulation.py b/backend/scripts/run_twitter_simulation.py
index d983538..61c6c13 100644
--- a/backend/scripts/run_twitter_simulation.py
+++ b/backend/scripts/run_twitter_simulation.py
@@ -442,23 +442,23 @@ class TwitterSimulationRunner:
         if not llm_model:
             llm_model = self.config.get("llm_model", "gpt-4o-mini")
         
-        # 设置 camel-ai 所需的环境变量
-        if llm_api_key:
-            os.environ["OPENAI_API_KEY"] = llm_api_key
-        
-        if not os.environ.get("OPENAI_API_KEY"):
-            raise ValueError("缺少 API Key 配置，请在项目根目录 .env 文件中设置 LLM_API_KEY")
-        
-        if llm_base_url:
-            os.environ["OPENAI_BASE_URL"] = llm_base_url
+        if not llm_api_key:
+            raise ValueError("LLM_API_KEY not configured. Set it in .env file.")
         
         print(f"LLM配置: model={llm_model}, base_url={llm_base_url[:40] if llm_base_url else '默认'}...")
         
-        # camel-ai reads OPENAI_API_KEY from env automatically
+        # Pass api_key and base_url via model_config_dict
+        # camel-ai extracts these for the OpenAI client constructor
+        model_config = {}
+        if llm_api_key:
+            model_config["api_key"] = llm_api_key
+        if llm_base_url:
+            model_config["base_url"] = llm_base_url
         
         return ModelFactory.create(
             model_platform=ModelPlatformType.OPENAI,
             model_type=llm_model,
+            model_config_dict=model_config,
         )
     
     def _get_active_agents_for_round(