diff --git a/source/dnode/vnode/src/tsdb/tsdbRead.c b/source/dnode/vnode/src/tsdb/tsdbRead.c
index 6ea270e5f4..e919593f90 100644
--- a/source/dnode/vnode/src/tsdb/tsdbRead.c
+++ b/source/dnode/vnode/src/tsdb/tsdbRead.c
@@ -693,6 +693,7 @@ static int32_t doLoadFileBlock(STsdbReader* pReader, SArray* pIndexList, SBlockN
 
     tMapDataReset(&pScanInfo->mapData);
     tsdbReadDataBlk(pReader->pFileReader, pBlockIdx, &pScanInfo->mapData);
+    taosArrayEnsureCap(pScanInfo->pBlockList, pScanInfo->mapData.nItem);
 
     sizeInDisk += pScanInfo->mapData.nData;
     for (int32_t j = 0; j < pScanInfo->mapData.nItem; ++j) {