diff --git a/pkg/controller/podgroup.go b/pkg/controller/podgroup.go
index ed3f2bd4..37cfa9bf 100644
--- a/pkg/controller/podgroup.go
+++ b/pkg/controller/podgroup.go
@@ -356,7 +356,12 @@ func calPGMinResource(minMember *int32, mpiJob *kubeflow.MPIJob, pcLister schedu
 
 	sort.Sort(sort.Reverse(order))
 	// Launcher + Worker > minMember
-	if minMember != nil && *order[0].Replicas+*order[1].Replicas > *minMember {
+	replicas := *order[0].Replicas
+	if len(order) > 1 {
+		// When using runLauncherAsWorker, there may be no worker.
+		replicas += *order[1].Replicas
+	}
+	if minMember != nil && replicas > *minMember {
 		// If the launcher and workers have the same priority, it treats workers as a lower priority.
 		if order[0].priority == order[1].priority {
 			wIndex := order.getWorkerIndex()
diff --git a/pkg/controller/podgroup_test.go b/pkg/controller/podgroup_test.go
index c1d7e040..1a7574ba 100644
--- a/pkg/controller/podgroup_test.go
+++ b/pkg/controller/podgroup_test.go
@@ -38,6 +38,11 @@ var (
 		corev1.ResourceMemory: resource.MustParse("512Gi"),
 		"example.com/gpu":     resource.MustParse("40"),
 	}
+
+	minResourcesNoMinMember = &corev1.ResourceList{
+		corev1.ResourceCPU:    resource.MustParse("1"),
+		corev1.ResourceMemory: resource.MustParse("2Gi"),
+	}
 )
 
 func TestNewPodGroup(t *testing.T) {
@@ -208,6 +213,73 @@ func TestNewPodGroup(t *testing.T) {
 				},
 			},
 		},
+		"no worker no MinResources": {
+			mpiJob: &kubeflow.MPIJob{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+					Annotations: map[string]string{
+						volcanov1beta1.QueueNameAnnotationKey: "project-x",
+					},
+				},
+				Spec: kubeflow.MPIJobSpec{
+					RunLauncherAsWorker: ptr.To[bool](true),
+					RunPolicy: kubeflow.RunPolicy{
+						SchedulingPolicy: &kubeflow.SchedulingPolicy{
+							MinAvailable:           ptr.To[int32](1),
+							Queue:                  "project-y",
+							PriorityClass:          "high",
+							ScheduleTimeoutSeconds: ptr.To[int32](100),
+						},
+					},
+					MPIReplicaSpecs: map[kubeflow.MPIReplicaType]*kubeflow.ReplicaSpec{
+						kubeflow.MPIReplicaTypeLauncher: {
+							Replicas: ptr.To[int32](1),
+							Template: corev1.PodTemplateSpec{
+								Spec: corev1.PodSpec{
+									Containers: []corev1.Container{{
+										Resources: corev1.ResourceRequirements{
+											Requests: corev1.ResourceList{
+												corev1.ResourceCPU:    resource.MustParse("1"),
+												corev1.ResourceMemory: resource.MustParse("2Gi"),
+											},
+										},
+									}},
+								},
+							},
+						},
+					},
+				},
+			},
+			wantVolcanoPG: &volcanov1beta1.PodGroup{
+				TypeMeta: metav1.TypeMeta{
+					APIVersion: volcanov1beta1.SchemeGroupVersion.String(),
+					Kind:       "PodGroup",
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: volcanov1beta1.PodGroupSpec{
+					MinMember:         1,
+					Queue:             "project-y",
+					PriorityClassName: "high",
+					MinResources:      minResourcesNoMinMember,
+				},
+			},
+			wantSchedPG: &schedv1alpha1.PodGroup{
+				TypeMeta: metav1.TypeMeta{
+					APIVersion: schedv1alpha1.SchemeGroupVersion.String(),
+					Kind:       "PodGroup",
+				},
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: schedv1alpha1.PodGroupSpec{
+					MinMember:              1,
+					MinResources:           *minResourcesNoMinMember,
+					ScheduleTimeoutSeconds: ptr.To[int32](100),
+				},
+			},
+		},
 	}
 	for name, tc := range testCases {
 		t.Run(name, func(t *testing.T) {
@@ -447,6 +519,39 @@ func TestCalculatePGMinResources(t *testing.T) {
 				corev1.ResourceMemory: resource.MustParse("65Gi"),
 			},
 		},
+		"without worker without priorityClass": {
+			minMember: 3,
+			job: &kubeflow.MPIJob{
+				ObjectMeta: metav1.ObjectMeta{
+					Name: "test",
+				},
+				Spec: kubeflow.MPIJobSpec{
+					MPIReplicaSpecs: map[kubeflow.MPIReplicaType]*kubeflow.ReplicaSpec{
+						kubeflow.MPIReplicaTypeLauncher: {
+							Replicas: ptr.To[int32](1),
+							Template: corev1.PodTemplateSpec{
+								Spec: corev1.PodSpec{
+									Containers: []corev1.Container{
+										{
+											Resources: corev1.ResourceRequirements{
+												Requests: corev1.ResourceList{
+													corev1.ResourceCPU:    resource.MustParse("2"),
+													corev1.ResourceMemory: resource.MustParse("1Gi"),
+												},
+											},
+										},
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+			want: &corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("2"),
+				corev1.ResourceMemory: resource.MustParse("1Gi"),
+			},
+		},
 	}
 	for name, tc := range volcanoTests {
 		t.Run(name, func(t *testing.T) {