using System.Runtime.InteropServices;

using System.Reflection;

[DllImport("user32.dll")]

static extern IntPtr LoadCursorFromFile( string fileName );

private void Form1_Load(object sender, EventArgs e)

  {

      Cursor customCursor = new Cursor(Cursor.Current.Handle);

      IntPtr customCursorHandle = LoadCursorFromFile("你的自定义鼠标指针的路径");

      customCursor.GetType().InvokeMember("handle", BindingFlags.Public |

      BindingFlags.NonPublic | BindingFlags.Instance |

      BindingFlags.SetField, null, customCursor,

     new object[] { customCursorHandle });

     this.Cursor = customCursor;

  }