Abstract: China-Brazil Earth Resource Satellite is based on the field of land resources and mainly focuses on high and moderate resolution optical remote sensing. The main payload on the 04A satellite adopts off-axis TMA optical system with large field of view and low distortion. In order to solve the problem of harsh mechanical environment caused by vertical installation of the camera, a solution of box-type main structure and passive vibration isolation is proposed. We start with main frame design, mirror support and vibration isolation measures, the static and dynamic modeling of the off-axis TMA camera is carried out, and the structural form is optimized. Through the optical-mechanical integration analysis, the natural frequency of the structure is improved, the first-order frequency reaches 168 Hz, and the mechanical response of the transmitting section is reduced, the mechanical response of the key components of the camera is attenuated by more than 50%, and the transfer function of the camera system is greater than 0.18. The ground environment test and in-orbit test show that the optical mechanical structure design is reasonable, the mechanical and vibration isolation performance meet the use requirements.