diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index bd46bab84ea7b64a7cdde552a3a77592265ffc60..3538293a61103a1a2b74d878ee2c1f1571830dbb 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -4349,7 +4349,7 @@ int32_t tsdbGetFileBlocksDistInfo(STsdbReader* pReader, STableBlockDistInfo* pTa
         pTableBlockInfo->numOfSmallBlocks += 1;
       }
 
-      pTableBlockInfo->totalSize = pBlock->aSubBlock[0].szBlock;
+      pTableBlockInfo->totalSize += pBlock->aSubBlock[0].szBlock;
 
       int32_t bucketIndex = getBucketIndex(pTableBlockInfo->defMinRows, bucketRange, numOfRows);
       pTableBlockInfo->blockRowsHisto[bucketIndex]++;