diff --git a/source/libs/executor/src/tsort.c b/source/libs/executor/src/tsort.c
index c56dab1e33..18c46cd03f 100644
--- a/source/libs/executor/src/tsort.c
+++ b/source/libs/executor/src/tsort.c
@@ -24,6 +24,7 @@
 #include "tpagedbuf.h"
 #include "tsort.h"
 #include "tutil.h"
+#include "tsimplehash.h"
 
 struct STupleHandle {
   SSDataBlock* pBlock;
@@ -975,15 +976,27 @@ static int32_t createBlocksMergeSortInitialSources(SSortHandle* pHandle) {
   int32_t      szSort = 0;
 
   SArray* aBlkSort = taosArrayInit(8, POINTER_BYTES);
+  SSHashObj* mUidBlk = tSimpleHashInit(64, taosGetDefaultHashFunction(TSDB_DATA_TYPE_UBIGINT));
   while (1) {
     SSDataBlock* pBlk = pHandle->fetchfp(pSrc->param);
 
     if (pBlk != NULL) {
       szSort += blockDataGetSize(pBlk);
-      SSDataBlock* blk = createOneDataBlock(pBlk, true);
-      taosArrayPush(aBlkSort, &blk);
+
+      void* ppBlk = tSimpleHashGet(mUidBlk, &pBlk->info.id.uid, sizeof(pBlk->info.id.uid));
+      if (ppBlk != NULL) {
+        SSDataBlock* tBlk = *(SSDataBlock**)(ppBlk);
+        blockDataMerge(tBlk, pBlk);
+      } else {
+        SSDataBlock* tBlk = createOneDataBlock(pBlk, true);
+        tSimpleHashPut(mUidBlk, &pBlk->info.id.uid, sizeof(pBlk->info.id.uid), &tBlk, POINTER_BYTES);
+        taosArrayPush(aBlkSort, &tBlk);
+      }
     }
+
     if ((pBlk != NULL && szSort > maxBufSize) || (pBlk == NULL && szSort > 0)) {
+      tSimpleHashClear(mUidBlk);
+
       int64_t p = taosGetTimestampUs();
       sortBlocksToExtSource(pHandle, aBlkSort, pOrder, aExtSrc);
       int64_t el = taosGetTimestampUs() - p;
@@ -1000,7 +1013,7 @@ static int32_t createBlocksMergeSortInitialSources(SSortHandle* pHandle) {
       break;
     };
   }
-
+  tSimpleHashCleanup(mUidBlk);
   taosArrayDestroy(aBlkSort);
   tsortClearOrderdSource(pHandle->pOrderedSource, NULL, NULL);
   taosArrayAddAll(pHandle->pOrderedSource, aExtSrc);