diff --git a/backend/app/services/ontology_generator.py b/backend/app/services/ontology_generator.py
index 01a3d799..3a8f2be6 100644
--- a/backend/app/services/ontology_generator.py
+++ b/backend/app/services/ontology_generator.py
@@ -217,7 +217,7 @@ class OntologyGenerator:
         result = self.llm_client.chat_json(
             messages=messages,
             temperature=0.3,
-            max_tokens=4096
+            max_tokens=16384
         )
         
         # 验证和后处理
diff --git a/backend/app/utils/llm_client.py b/backend/app/utils/llm_client.py
index 6c1a81f4..b4c6e2f2 100644
--- a/backend/app/utils/llm_client.py
+++ b/backend/app/utils/llm_client.py
@@ -88,7 +88,6 @@ class LLMClient:
             messages=messages,
             temperature=temperature,
             max_tokens=max_tokens,
-            response_format={"type": "json_object"}
         )
         # 清理markdown代码块标记
         cleaned_response = response.strip()