Abstract: ZY 3 is the first Chinese civilian high resolution stereo mapping satellite. For ensuring the accuracy of mapping and positioning, the paramters of scanner must be carried out the on orbit calibration. In this paper, the piecewise polynomial error model are proposed during the analysis of ZY 3satellite’s imaging properties and physical structure.The piecepoint with weight polynomial model of attitude and orbit is proposed basing on the analysis for ZY 3’s attitude and orbit. The geometric calibration experiments were carried out with the high precision analogue data of ZY 3，and the result of experiement verified the piecewise polynomial model and the piecepoint with weight polynomial model are more suitable for the on orbit calibration of ZY 3.