diff --git a/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java b/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java
index 7e6d81db7935112..b3638f3b75bf564 100644
--- a/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java
+++ b/fe/fe-core/src/main/java/org/apache/doris/planner/OlapScanNode.java
@@ -948,9 +948,11 @@ public void computeSampleTabletIds() {
         }
         for (Long partitionId : selectedPartitionIds) {
             final Partition partition = olapTable.getPartition(partitionId);
-            final MaterializedIndex selectedTable = partition.getIndex(selectedIndexId);
-            selectedRows += selectedTable.getRowCount();
-            selectedPartitionList.add(partitionId);
+            final MaterializedIndex selectedIndex = partition.getIndex(selectedIndexId);
+            if (selectedIndex != null) {
+                selectedRows += selectedIndex.getRowCount();
+                selectedPartitionList.add(partitionId);
+            }
         }
         selectedPartitionList.sort(Comparator.naturalOrder());
 
@@ -970,7 +972,7 @@ public void computeSampleTabletIds() {
         // 3. Sampling partition. If Seek is specified, the partition will be the same for each sampling.
         long hitRows = 0; // The number of rows hit by the tablet
         long partitionSeek = tableSample.getSeek() != -1
-                ? tableSample.getSeek() : (long) (new SecureRandom().nextDouble() * selectedPartitionIds.size());
+                ? tableSample.getSeek() : (long) (new SecureRandom().nextDouble() * selectedPartitionList.size());
         for (int i = 0; i < selectedPartitionList.size(); i++) {
             int seekPid = (int) ((i + partitionSeek) % selectedPartitionList.size());
             final Partition partition = olapTable.getPartition(selectedPartitionList.get(seekPid));