diff --git a/inc/hgl/platform/compiler/Microsoft.h b/inc/hgl/platform/compiler/Microsoft.h
index b799d8b..dd0d175 100644
--- a/inc/hgl/platform/compiler/Microsoft.h
+++ b/inc/hgl/platform/compiler/Microsoft.h
@@ -24,7 +24,9 @@
 #define HGL_FMT_U64            "%I64u"
 //参考文档最后查阅支持版本为VC2013，网址：http://msdn.microsoft.com/en-us/library/tcxf1dw6.aspx
 //--------------------------------------------------------------------------------------------------
+#ifndef _USE_MATH_DEFINES
 #define _USE_MATH_DEFINES                // 使用数学常数定义
+#endif//_USE_MATH_DEFINES
 //--------------------------------------------------------------------------------------------------
 #ifndef _CRT_SECURE_NO_WARNINGS
 #define _CRT_SECURE_NO_WARNINGS