diff --git a/NineChess/src/aithread.cpp b/NineChess/src/aithread.cpp
index d9bb765d..cf0820f8 100644
--- a/NineChess/src/aithread.cpp
+++ b/NineChess/src/aithread.cpp
@@ -70,7 +70,9 @@ void AiThread::setAi(const NineChess &chess)
 
 #ifdef HASH_MAP_ENABLE
     // 新下一盘前清除哈希表 (注意可能同时存在每步之前清除)
+#ifdef CLEAR_HASH_MAP
     ai_ab.clearHashMap();
+#endif
 #endif
 
     mutex.unlock();
diff --git a/NineChess/src/config.h b/NineChess/src/config.h
index 4ee277a5..4add01bf 100644
--- a/NineChess/src/config.h
+++ b/NineChess/src/config.h
@@ -30,6 +30,7 @@
 #define IDS_SUPPORT
 
 #define HASH_MAP_ENABLE
+//#define CLEAR_HASH_MAP
 
 #define MEMORY_POOL
 
diff --git a/NineChess/src/ninechessai_ab.cpp b/NineChess/src/ninechessai_ab.cpp
index 4c030c57..4816b856 100644
--- a/NineChess/src/ninechessai_ab.cpp
+++ b/NineChess/src/ninechessai_ab.cpp
@@ -669,7 +669,9 @@ int NineChessAi_ab::alphaBetaPruning(int depth)
     // 深化迭代
     for (int i = 2; i < d; i += 2) {
 #ifdef HASH_MAP_ENABLE
+#ifdef CLEAR_HASH_MAP
         clearHashMap();   // 每次走子前清空哈希表
+#endif
 #endif
         alphaBetaPruning(i, -INF_VALUE, INF_VALUE, rootNode);
     }
@@ -678,7 +680,9 @@ int NineChessAi_ab::alphaBetaPruning(int depth)
 #endif /* IDS_SUPPORT */
 
 #ifdef HASH_MAP_ENABLE
+#ifdef CLEAR_HASH_MAP
     clearHashMap();  // 每次走子前清空哈希表
+#endif
 #endif
 
     value = alphaBetaPruning(d, -INF_VALUE /* alpha */, INF_VALUE /* beta */, rootNode);