The measurement accuracy of angle is the most important specification in the metrological confirmation of photo-electronic tracking system. Usually, taking the calibration tower and the azimuth mark as the primary standard, the single error is calibrated with complicated process and long period. In order to improve the accuracy of measurement and shorten the confirmation periad and applying the star calibration technology, principle, method and program of the photo-electronic tracking system have been researched on the besis of practice. The error source, establishment of mathematic model and its resoluing method are discussed in this paper.