先写个脚本用来打印选中的对象所属类型

using UnityEngine;
using UnityEditor;

public class TestEditor : MonoBehaviour {

    [MenuItem("Assets/ShowSelectionType", false, 0)]
    private static void ShowSelectionType()
    {
        UnityEngine.Object obj = Selection.activeObject;
        Debug.Log(PrefabUtility.GetPrefabType(obj));
    }
}

PrefabType.Prefab

PrefabType.PrefabInstance

把Prefab从Project面板拖到Hierarchy并改名为PrefabInstance

PrefabType.MissingPrefabInstance

在Project里随便创建个prefab并拖到Hierarchy改名为MissingPrefabInstance,然后把Project里的这个prefab删除掉(即，使它关联的prefab丢失)

PrefabType.DisconnectedPrefabInstance

把原本在PrefabInstance下面的DisconnectedPrefabInstace拖出来，这就断开了此对象与Prefab的关联。

PrefabType.ModelPrefabInstance与PrefabType.DisconnectedPrefabInstance同理