A large projection image screen device having a seesaw structure for virtual reality where a chair is provided on one side of a lever and an image system is provided on the other side of the lever. Several rotation shafts are provided below the lever for up down rotation, left right rotation and front rear rotation, where when the chair and the screen are rotated up and downward, left and rightward, and front and rearward, a user on the chair views the images at the same view angle as the rotation angle of the screen through a location tracing device.