The camera shooting index device can let the user use camera to take the entire display zone of display screen by connecting communication interface with host and to carry on edge retouch processing for the taken image with image processing circuit so coordinate values of four angles in the image at display zone is obtained and furthermore, coordinate value of camera aiming point at actual display screen is calculated out by calculation program and finally the actual coordinate value is sent to the host for relative formula processing. It can be installed at any display screen for shooting game.