In this paper,Code V software is used to design a space optical remote sensing system.The F number of the system is 2,the diameter of the entry pupil is 125mm,the diameter of the exit pupil is 39mm,the distortion is less than 0.5%,and the root mean square diameter of the dot plot is less than 5μm.According to the basic theory of optical thin film,the reflective film with R>98.5% at wavelength 1064±5 nm after nickel plating on the surface of aluminum based silicon carbide was designed.Aluminum based silicon carbide was selected as the substrate material of the mirror,and the aluminum based silicon carbide substrate nickel coated aluminum film was prepared on the OZZSQ900 box vacuum coating machine by using the modified nickel layer.UV 2600i spectrometer was used to test the reflection spectrum of the coated sample,and the test results met the design requirements.The research has important practical significance and engineering value.