diff --git a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/distribute/worker/job/AbstractUnassignedScanJob.java b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/distribute/worker/job/AbstractUnassignedScanJob.java
index 95052aeda68211b..1caa65d0ccd1334 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/distribute/worker/job/AbstractUnassignedScanJob.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/distribute/worker/job/AbstractUnassignedScanJob.java
@@ -92,7 +92,7 @@ protected List<AssignedJob> insideMachineParallelization(
             int instanceNum = degreeOfParallelism(scanSourceMaxParallel);
 
             List<ScanSource> instanceToScanRanges;
-            if (useLocalShuffleToAddParallel) {
+            if (useLocalShuffleToAddParallel && instanceNum > 1) {
                 // only generate one instance to scan all data, in this step
                 instanceToScanRanges = scanSource.parallelize(
                         scanNodes, 1