According to the assembly requirements of the space camera's primary and secondary mirror system, this paper proposes the assembly process of carbon fiber truss fuselage's primary and secondary mirror system based on adhesive error compensation technology. The process starts from a system point of view, the adhesive bonding of the truss fuselage was unified with the assembly of the primary and secondary mirror system. The adhesive technology was used to compensate the machining errors of the structural parts, and the adhesive bonding of the truss fuselage and the optical axis consistency assembly of primary and secondary mirror system are realized in the process of one adjustment. According to this assembly process idea, the assembly process of primary and secondary mirror system was designed. Firstly, the optical axis of the primary mirror and the optical axis of the secondary mirror were calibrated by the principle of autocollimation, and the optical axis was guided to the cross reticule as the reference for subsequent installation and adjustment. Secondly, in order to realize this process method, the assembly and adjustment platform of the primary and secondary mirror was designed and built. In addition, the factors that affect the assembly precision of the primary and secondary mirror system are analyzed one by one, and the calculation method of system assembly error is obtained. This assembly method has been successfully applied to a space camera. After assembly, the coaxiality between the optical axis of the primary mirror and the optical axis of the secondary mirror is better than 0.02mm, the Angle between the optical axis is better than 10 ", and the wavefront of the primary and secondary mirror system is close to the optical design index. The assembly method presented in this paper provides a technical reference for the assembly of similar large aperture optical machine system. © 2021 SPIE