diff --git a/internal/datanode/data_node.go b/internal/datanode/data_node.go
index 4673f538e3..a3de56a3d5 100644
--- a/internal/datanode/data_node.go
+++ b/internal/datanode/data_node.go
@@ -1253,6 +1253,7 @@ func assignSegmentFunc(node *DataNode, req *datapb.ImportTaskRequest) importutil
 		colID := req.GetImportTask().GetCollectionId()
 		segmentIDReq := composeAssignSegmentIDRequest(1, shardID, chNames, colID, partID)
 		targetChName := segmentIDReq.GetSegmentIDRequests()[0].GetChannelName()
+		logFields = append(logFields, zap.Int64("collection ID", colID))
 		logFields = append(logFields, zap.String("target channel name", targetChName))
 		log.Info("assign segment for the import task", logFields...)
 		resp, err := node.dataCoord.AssignSegmentID(context.Background(), segmentIDReq)
@@ -1313,6 +1314,7 @@ func createBinLogsFunc(node *DataNode, req *datapb.ImportTaskRequest, schema *sc
 			log.Info("fields data is empty, no need to generate binlog", logFields...)
 			return nil, nil, nil
 		}
+		logFields = append(logFields, zap.Int("row count", rowNum))
 
 		colID := req.GetImportTask().GetCollectionId()
 		fieldInsert, fieldStats, err := createBinLogs(rowNum, schema, ts, fields, node, segmentID, colID, partID)
@@ -1406,12 +1408,6 @@ func composeAssignSegmentIDRequest(rowNum int, shardID int, chNames []string,
 	// use the first field's row count as segment row count
 	// all the fields row count are same, checked by ImportWrapper
 	// ask DataCoord to alloc a new segment
-	log.Info("import task flush segment",
-		zap.Int("rowCount", rowNum),
-		zap.Any("channel names", chNames),
-		zap.Int64("collectionID", collID),
-		zap.Int64("partitionID", partID),
-		zap.Int("shardID", shardID))
 	segReqs := []*datapb.SegmentIDRequest{
 		{
 			ChannelName:  chNames[shardID],
diff --git a/internal/util/importutil/import_wrapper.go b/internal/util/importutil/import_wrapper.go
index 62110c4352..d8900ecc79 100644
--- a/internal/util/importutil/import_wrapper.go
+++ b/internal/util/importutil/import_wrapper.go
@@ -454,33 +454,39 @@ func (p *ImportWrapper) flushFunc(fields BlockData, shardID int, partitionID int
 	}
 
 	// if fields data is empty, do nothing
-	var rowNum int
+	rowNum := 0
 	memSize := 0
 	for _, field := range fields {
 		rowNum = field.RowNum()
 		memSize += field.GetMemorySize()
-		break
 	}
 	if rowNum <= 0 {
 		log.Warn("import wrapper: fields data is empty", logFields...)
 		return nil
 	}
 
+	logFields = append(logFields, zap.Int("rowNum", rowNum), zap.Int("memSize", memSize))
+	log.Info("import wrapper: flush block data to binlog", logFields...)
+
 	// if there is no segment for this shard, create a new one
 	// if the segment exists and its size almost exceed segmentSize, close it and create a new one
 	var segment *WorkingSegment
 	if shard, ok := p.workingSegments[shardID]; ok {
-		if segment, exists := shard[partitionID]; exists {
-			// the segment already exists, check its size, if the size exceeds(or almost) segmentSize, close the segment
-			if int64(segment.memSize)+int64(memSize) >= p.segmentSize {
-				err := p.closeWorkingSegment(segment)
+		if segmentTemp, exists := shard[partitionID]; exists {
+			log.Info("import wrapper: compare working segment memSize with segmentSize",
+				zap.Int("memSize", segmentTemp.memSize), zap.Int64("segmentSize", p.segmentSize))
+			if int64(segmentTemp.memSize)+int64(memSize) >= p.segmentSize {
+				// the segment already exists, check its size, if the size exceeds(or almost) segmentSize, close the segment
+				err := p.closeWorkingSegment(segmentTemp)
 				if err != nil {
 					logFields = append(logFields, zap.Error(err))
 					log.Warn("import wrapper: failed to close working segment", logFields...)
 					return err
 				}
-				segment = nil
 				p.workingSegments[shardID][partitionID] = nil
+			} else {
+				// the exist segment size is small, no need to close
+				segment = segmentTemp
 			}
 		}
 	} else {