The invention provides a composite damping structure for an airborne photoelectric system. The composite damping structure comprises a round upper end cover, a round lower end cover connected with anairborne platform, a round bearing disc connected with the photoelectric system, eight steel wire rope dampers evenly distributed on the periphery, eight rubber dampers evenly distributed on the periphery and a cable connected with the photoelectric system and an upper computer. The upper end cover and the lower end cover are connected through bolts to form a cylindrical sealed inner cavity. The bearing disc is installed in the middle of the inner cavity, and the inner cavity is divided into an upper cavity and a lower cavity. The eight steel wire rope dampers and the eight rubber dampers areevenly distributed in the circumferential direction of the bearing disc in the lower cavity. The cable is arranged and connected into the upper cavity. According to the composite damping structure, the damping structure is externally moved from the interior of the photoelectric system to the position between the photoelectric system and the airborne platform, integrated and compact structure design is used in the aspect of design of the damping structure, the damping structure is designed as a half-closed device which can be replaced wholly, interior components of the damping structure are completely separated from the exterior harsh environment, and the high outer field maintenance and reliability are ensured.