diff --git a/controllers/pvc.go b/controllers/pvc.go
index 5b46aa3de..454709ce8 100644
--- a/controllers/pvc.go
+++ b/controllers/pvc.go
@@ -147,9 +147,10 @@ func (*MySQLClusterReconciler) needResizePVC(cluster *mocov1beta2.MySQLCluster,
 		pvcSet[pvc.Name] = pvc
 	}
 
+	resizeTarget := make(map[string]corev1.PersistentVolumeClaim)
+
 	for _, pvc := range cluster.Spec.VolumeClaimTemplates {
 		if _, ok := pvcSet[pvc.Name]; !ok {
-			delete(pvcSet, pvc.Name)
 			continue
 		}
 
@@ -160,20 +161,20 @@ func (*MySQLClusterReconciler) needResizePVC(cluster *mocov1beta2.MySQLCluster,
 
 		switch i := deployedSize.Cmp(wantSize.DeepCopy()); {
 		case i == 0: // volume size is equal
-			delete(pvcSet, pvc.Name)
 			continue
 		case i == 1: // volume size is greater
 			return nil, false, fmt.Errorf("failed to resize pvc %q, want size: %s, deployed size: %s: %w", pvc.Name, wantSize, deployedSize, ErrReduceVolumeSize)
 		case i == -1: // volume size is smaller
+			resizeTarget[pvc.Name] = pvcSet[pvc.Name]
 			continue
 		}
 	}
 
-	if len(pvcSet) == 0 {
+	if len(resizeTarget) == 0 {
 		return nil, false, nil
 	}
 
-	return pvcSet, true, nil
+	return resizeTarget, true, nil
 }
 
 func (r *MySQLClusterReconciler) isVolumeExpansionSupported(ctx context.Context, pvc *corev1.PersistentVolumeClaim) (bool, error) {
diff --git a/controllers/pvc_test.go b/controllers/pvc_test.go
index 29e855cca..f578b3aad 100644
--- a/controllers/pvc_test.go
+++ b/controllers/pvc_test.go
@@ -161,6 +161,46 @@ func TestNeedResizePVC(t *testing.T) {
 			wantResize: false,
 			wantError:  ErrReduceVolumeSize,
 		},
+		{
+			name:    "StatefulSet has more PVCs",
+			cluster: newMySQLClusterWithVolumeSize(resource.MustParse("1Gi")),
+			sts: func() *appsv1.StatefulSet {
+				sts := newStatefulSetWithVolumeSize(resource.MustParse("1Gi"))
+				pvc := corev1.PersistentVolumeClaim{
+					ObjectMeta: metav1.ObjectMeta{
+						Name: "new-data",
+					},
+					Spec: corev1.PersistentVolumeClaimSpec{
+						StorageClassName: pointer.String("default"),
+						Resources: corev1.ResourceRequirements{
+							Requests: corev1.ResourceList{corev1.ResourceStorage: resource.MustParse("1Gi")},
+						},
+					},
+				}
+
+				sts.Spec.VolumeClaimTemplates = append(sts.Spec.VolumeClaimTemplates, pvc)
+
+				return sts
+			}(),
+			wantResize: false,
+		},
+		{
+			name: "MySQLCluster has more PVCs",
+			cluster: func() *mocov1beta2.MySQLCluster {
+				cluster := newMySQLClusterWithVolumeSize(resource.MustParse("1Gi"))
+				pvc := mocov1beta2.PersistentVolumeClaim{
+					ObjectMeta: mocov1beta2.ObjectMeta{Name: "new-data"},
+					Spec: mocov1beta2.PersistentVolumeClaimSpecApplyConfiguration(*corev1ac.PersistentVolumeClaimSpec().
+						WithStorageClassName("default").WithResources(corev1ac.ResourceRequirements().
+						WithRequests(corev1.ResourceList{corev1.ResourceStorage: resource.MustParse("1Gi")}),
+					)),
+				}
+				cluster.Spec.VolumeClaimTemplates = append(cluster.Spec.VolumeClaimTemplates, pvc)
+				return cluster
+			}(),
+			sts:        newStatefulSetWithVolumeSize(resource.MustParse("1Gi")),
+			wantResize: false,
+		},
 	}
 
 	for _, tt := range tests {
@@ -178,6 +218,10 @@ func TestNeedResizePVC(t *testing.T) {
 				t.Fatalf("want resize %v, got %v", tt.wantResize, resize)
 			}
 
+			if len(tt.wantResizeTarget) != len(resizeTarget) {
+				t.Fatalf("want resize target length %v, got %v", len(tt.wantResizeTarget), len(resizeTarget))
+			}
+
 			for key, value := range tt.wantResizeTarget {
 				if diff := cmp.Diff(value, resizeTarget[key]); len(diff) != 0 {
 					t.Fatalf("want resize target %v, got %v", value, resizeTarget[key])