Abstract: Abstract：  The star camera optical system is the key technology to achieve high precision performance of the star camera. Based on the engineering practice, the index of image quality evaluation for star camera optical system is combed, and the index decomposition of star point centroid position and the decomposition process of optical system evaluation index are mainly discussed. The analysis shows that: a. both of the centroid position deviation and the central of star point deviation relative to the ideal image height need to be focused on. b. the rise of uniform temperature and the change of gradient temperature need to be taken into account in the optical design process. An example of the star camera optical system design is given, which is based on the double Gauss form, and the aberration theory is applied in the optimization process, with well heat dissipation design and distortion control. The centroid position consistency under different temperature conditions of different types of the fixed stars is analyzed. The results show that the optical system can meet the requirements of highprecision star camera specifications.

Key words: Keywords： star camera, optical design, imaging quality, centroid position accuracy