Abstract: According to the design index requirements of a space remote sensors secondary mirror, a lightweight mirror was designed by using the optimization solution function of ANASYS. In the design process, model parameters of the secondary mirror were set as variables and they were solved iteratively through the multi-parameter optimization design function of ANASYS to meet the size of the secondary mirrors under minimum quality and shape deformation. Finally, a secondary mirror mode which could meet design requirement l was got with the lightweight rate of 80.635%, the surface figure root-mean-square(RMS) value of6.953 nm and peak-valley(PV) value of 31.317nm.