diff --git a/App/lib/core/Handles/HandlesFunctions.py b/App/lib/core/Handles/HandlesFunctions.py
index 0a9449c..c19f159 100644
--- a/App/lib/core/Handles/HandlesFunctions.py
+++ b/App/lib/core/Handles/HandlesFunctions.py
@@ -470,6 +470,12 @@ def translate_function_def(trans: HT.Translator | t.CPtr,
 
     if is_extern_decl != 0:
         # 外部声明函数：生成 declare（仅声明，不定义）
+        # 先检查是否已由 forward_declare_functions 创建，避免重复 declare
+        existing_extern: llvmlite.Function | t.CPtr = HandlesExprCall.find_func_in_module(mod, mangled_name)
+        if existing_extern is not None:
+            # 已存在前向声明，复用之，不再重复创建
+            return 0
+
         func: llvmlite.Function | t.CPtr = llvmlite.create_declare(
             pool, mod, mangled_name, ret_ty)
         if func is None: