diff --git a/pkg/schedule/operator/operator.go b/pkg/schedule/operator/operator.go
index ab956d79c9e..9054983128b 100644
--- a/pkg/schedule/operator/operator.go
+++ b/pkg/schedule/operator/operator.go
@@ -18,6 +18,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"reflect"
+	"strconv"
 	"strings"
 	"sync/atomic"
 	"time"
@@ -61,6 +62,8 @@ var (
 	ExceedStoreLimit CancelReasonType = "exceed store limit"
 	// ExceedWaitLimit is the cancel reason when the operator exceeds the waiting queue limit.
 	ExceedWaitLimit CancelReasonType = "exceed wait limit"
+	// RelatedMergeRegion is the cancel reason when the operator is cancelled by related merge region.
+	RelatedMergeRegion CancelReasonType = "related merge region"
 	// Unknown is the cancel reason when the operator is cancelled by an unknown reason.
 	Unknown CancelReasonType = "unknown"
 )
@@ -115,6 +118,8 @@ func NewOperator(desc, brief string, regionID uint64, regionEpoch *metapb.Region
 // Sync some attribute with the given timeout.
 func (o *Operator) Sync(other *Operator) {
 	o.timeout = other.timeout
+	o.AdditionalInfos[string(RelatedMergeRegion)] = strconv.FormatUint(other.RegionID(), 10)
+	other.AdditionalInfos[string(RelatedMergeRegion)] = strconv.FormatUint(o.RegionID(), 10)
 }
 
 func (o *Operator) String() string {
diff --git a/pkg/schedule/operator/operator_controller.go b/pkg/schedule/operator/operator_controller.go
index d6b94d2996f..5581ecdd2d4 100644
--- a/pkg/schedule/operator/operator_controller.go
+++ b/pkg/schedule/operator/operator_controller.go
@@ -569,11 +569,27 @@ func (oc *Controller) removeOperatorLocked(op *Operator) bool {
 		oc.updateCounts(oc.operators)
 		operatorCounter.WithLabelValues(op.Desc(), "remove").Inc()
 		oc.ack(op)
+		if op.Kind()&OpMerge != 0 {
+			oc.removeRelatedMergeOperator(op)
+		}
 		return true
 	}
 	return false
 }
 
+func (oc *Controller) removeRelatedMergeOperator(op *Operator) {
+	relatedID, _ := strconv.ParseUint(op.AdditionalInfos[string(RelatedMergeRegion)], 10, 64)
+	if relatedOp := oc.operators[relatedID]; relatedOp != nil && relatedOp.Status() != CANCELED {
+		log.Info("operator canceled related merge region",
+			zap.Uint64("region-id", relatedOp.RegionID()),
+			zap.String("additional-info", relatedOp.GetAdditionalInfo()),
+			zap.Duration("takes", relatedOp.RunningTime()))
+		oc.removeOperatorLocked(relatedOp)
+		relatedOp.Cancel(RelatedMergeRegion)
+		oc.buryOperator(relatedOp)
+	}
+}
+
 func (oc *Controller) buryOperator(op *Operator) {
 	st := op.Status()
 
diff --git a/server/cluster/cluster_test.go b/server/cluster/cluster_test.go
index 1a5b64906bf..6271b17d462 100644
--- a/server/cluster/cluster_test.go
+++ b/server/cluster/cluster_test.go
@@ -2700,6 +2700,47 @@ func TestCheckerIsBusy(t *testing.T) {
 	checkRegionAndOperator(re, tc, co, num, 0)
 }
 
+func TestMergeRegionCancelOneOperator(t *testing.T) {
+	re := require.New(t)
+	tc, co, cleanup := prepare(nil, nil, nil, re)
+	defer cleanup()
+
+	source := core.NewRegionInfo(
+		&metapb.Region{
+			Id:       1,
+			StartKey: []byte(""),
+			EndKey:   []byte("a"),
+		},
+		nil,
+	)
+	target := core.NewRegionInfo(
+		&metapb.Region{
+			Id:       2,
+			StartKey: []byte("a"),
+			EndKey:   []byte("t"),
+		},
+		nil,
+	)
+	re.NoError(tc.putRegion(source))
+	re.NoError(tc.putRegion(target))
+
+	// Cancel source region.
+	ops, err := operator.CreateMergeRegionOperator("merge-region", tc, source, target, operator.OpMerge)
+	re.NoError(err)
+	re.Len(ops, co.GetOperatorController().AddWaitingOperator(ops...))
+	// Cancel source operator.
+	co.GetOperatorController().RemoveOperator(co.GetOperatorController().GetOperator(source.GetID()))
+	re.Len(co.GetOperatorController().GetOperators(), 0)
+
+	// Cancel target region.
+	ops, err = operator.CreateMergeRegionOperator("merge-region", tc, source, target, operator.OpMerge)
+	re.NoError(err)
+	re.Len(ops, co.GetOperatorController().AddWaitingOperator(ops...))
+	// Cancel target operator.
+	co.GetOperatorController().RemoveOperator(co.GetOperatorController().GetOperator(target.GetID()))
+	re.Len(co.GetOperatorController().GetOperators(), 0)
+}
+
 func TestReplica(t *testing.T) {
 	re := require.New(t)