Abstract: This paper proposes an accurately calibration method which is suitable for the scene, on the issues of multiple subsystems relative position detecting complexity in a ball screen projection point targets tracking system. Take the ball screen as the world coordinate system, and mark center of the ball by subsystem to implement coordinate transformation of the projection point among the subsystems. The author studies the calibration principle and the projecting method, and provides a solution. Through Matlab simulation analysis of the error factor, simulated results show that the ball screen calibration precision can be effectively improved by reducing the distance between the subsystem and its center or perfecting the projection point spatial distribution. Eventually, this paper presents a calibration method based on the TLS and designs a virtual sphere, calibration device and finishes the experiments. The experimental results meet the demand of quick and accurate site calibration.