The invention discloses a folding fixed-surface reflector. The folding fixed-surface reflector comprises a large-aperture fixed-surface reflector (more than 3m), an unfolding arm, a two-dimensional rotating mechanism, a self-driven hinge and a locking and releasing device. The antenna is simple in structure and good in universality, the double-layer folding layout of the large-aperture reflector and the long unfolding arm can be achieved, and therefore, the long-focus layout of the antenna with the satellite height being two times or above is achieved, higher flexibility is brought to the antenna layout, and the antenna layout is not limited by envelope limitation of a satellite body any more. The long-focus multi-beam antenna is suitable for the development of long-focus multi-beam antennas in the future, and has wide applicability and popularization and application values.