Abstract: The aiming axis could affect the angle measurement accuracy of panoramic periscopic system. According to the typical opto-mechanical structure of the panoramic periscopic system, the error sources of aiming axis precision were analyzed. The calculation model was established by using the vector reflection theory and rotation principle, and the influence of azimuth axis，pitch axis, optical axis and reflector errors on the aiming axis was provided clearly. Meanwhile, the corresponding adjustment scheme was determined, each control point in the adjusting process was made clearly, and the debugging and testing methods were also determined. The test results show that the aiming axis accuracy is up to 0.1 mrad.