diff --git a/source/libs/index/inc/index_tfile.h b/source/libs/index/inc/index_tfile.h
index cf6341ce9cd83712f8fb7cf5e0db136ced774c9a..b19b887e9f86a482634b8c0877c1e4c079ac9f44 100644
--- a/source/libs/index/inc/index_tfile.h
+++ b/source/libs/index/inc/index_tfile.h
@@ -66,6 +66,7 @@ typedef struct TFileWriter {
   uint32_t    offset;
 } TFileWriter;
 
+// multi reader and single write
 typedef struct TFileReader {
   T_REF_DECLARE()
   Fst*        fst;
diff --git a/source/libs/index/src/index_tfile.c b/source/libs/index/src/index_tfile.c
index 9acd9f687019be78ab65f0775933cbfd6c22a32b..1cd5673faaf7f01980c803b2a26eee8e523ea8de 100644
--- a/source/libs/index/src/index_tfile.c
+++ b/source/libs/index/src/index_tfile.c
@@ -134,8 +134,15 @@ TFileReader* tfileCacheGet(TFileCache* tcache, TFileCacheKey* key) {
 void tfileCachePut(TFileCache* tcache, TFileCacheKey* key, TFileReader* reader) {
   char buf[128] = {0};
   tfileSerialCacheKey(key, buf);
-  tfileReadRef(reader);
+  // remove last version index reader
+  TFileReader** p = taosHashGet(tcache->tableCache, buf, strlen(buf));
+  if (*p != NULL) {
+    TFileReader* oldReader = *p;
+    taosHashRemove(tcache->tableCache, buf, strlen(buf));
+    tfileReadUnRef(oldReader);
+  }
 
+  tfileReadRef(reader);
   taosHashPut(tcache->tableCache, buf, strlen(buf), &reader, sizeof(void*));
   return;
 }