Update app.py

app.py

@@ -40,7 +40,17 @@ Question:
 <|im_start|>assistant
 """
     PROMPT = PromptTemplate(template=prompt_template, input_variables=["context", "question"])
-    qa_chain = RetrievalQA.from_chain_type(llm=llm, chain_type="stuff", retriever=vector_store.as_retriever(search_kwargs={"k": 3}), chain_type_kwargs={"prompt": PROMPT})
+    retriever = vector_store.as_retriever(
+    search_type="similarity_score_threshold",
+    search_kwargs={'score_threshold': 0.3, 'k': 3}
+)
+
+    qa_chain = RetrievalQA.from_chain_type(
+    llm=llm,
+    chain_type="stuff",
+    retriever=retriever, # 使用我们新创建的retriever
+    chain_type_kwargs={"prompt": PROMPT}
+)
     print("✅ RAG管道加载完毕！")
     return qa_chain