Based on the structural complexity and high performance requirements of space remote sensor reflector component, the design method of space remote sensor reflector component was studied. A method which was a combining method with the experience design, the topology optimization design and the size parameter optimization design was put forward, which can make the design result fast convergence, getting the optimal design structure. A reflector component structure design of a space remote sensor was achieved with this method, by means of the finite element analysis techniques, the shape error variation RMS and PV of optical reflector component which characterized the image quality of the component were got, and dynamic simulation calculation was carried out. Finally, the correctness of the finite element analysis results and the rationality of the design were validated by environmental testing. The test results show that the RMS meet the design index under the comprehensive influence of gravity load, thermal load which is in the control range, reflector surface machining residual error and assembly error, and that the overall structure has a high enough dynamic stiffness and reasonable distribution of modal, the dynamic performance of the reflector component is good and meets the application requirement. In view of the reflector components design, this method is an effective and reliable design method.