Plane normal direction has been towards the camera！Thankyou!
If I understand your question correctly, you want the plane to always face the camera.
The simplest way to do this would be to make the camera the parent of the plane.
Set your camera’s rotation to (0,0,0), then rotate your plane to face the camera (hold ctrl to rotate in 15 degree intervals). Then you simply drag the plane onto the camera in the hierarchy.
The plane will now rotate along with the camera whenever the camera’s rotation is changed, either in game or in the editor.