In order to meet the requirements of high-precision alignment of primary and secondary mirrors of space camera in thermal environment, we develop a new supporting structure which can eliminate heat affect between mirrors automatically. Through the simulation analysis, we have verified this structural design is feasible. According to requirements of the optical system, an integrated machining scheme with three-bar supporting structure for the secondary mirror is proposed. The automatic athermalization of the primary and secondary mirrors supporting structure is confirmed by structural analysis and optimization. The displacement between the primary mirror and secondary mirrors in the thermal environment range of-20° ? +60°C is analyzed by using the PATRAN software, and the results show the position change is within 0.01mm. The structural size of the secondary mirror supporting cylinder is optimized, and the effect of stray light suppression for the multilayer sleeve visor is analyzed and verified by using the TRACEPRO software. The results show that the proposed structural design can achieve the high stability of the primary and secondary mirrors supporting structure and the good effect of stray light suppression. ? 2019 SPIE.