As the precision of existing projector calibration algorithms is low,a new calibration method based on the optimal matching area is proposed according to projector nonlinear model. Firstly,the optimal matching area is obtained through the experiments. Then,local homographies of corners in the optimal matching area are computed. Finally,the camera calibration method is used to calibrate the projector which reach the sub-pixel precision. The experiment results show that the proposed projector calibration algorithm is easy to operate. The calibration precision can achieve 0. 10617 pixel. The runtime costs 0.1907 s and point cloud density is 9.14 per mm2,which meets the measurement requirements of high precision.