Abstract: Based on Zhang’s method，the calibration method based on the centers of circles on a 2D plane is proposed.By contrasting this method with another two methods，based on corners of squares and based on centers of squares，the validity of this method presented in this paper is proved.In addition to，the implicit camera system model is made with BP neural network simulating the relationship between the 3D objects and its images in the stereo system，which avoiding the system errors caused by unperfected mathematic relation.Experiments show that the high calibration precision can be got by this way.