Thin film diffractive lens is an important development direction in space lightweight imaging. High-performance polyimide film materials are widely used because of their good comprehensive properties, but their low visible light transmittance and unstable performance in space environments limit their development in the field of substrates for space thin film optical mirrors. In this paper, SiO₂ antireflection film was prepared on the surface of the Fresnel diffraction lens by the sol-gel dip-pulling method. This composite structure design improves the visible light transmittance of polyimide film on the one hand, and improves its radiation resistance to space environment through surface silicon dioxide film on the other hand. This study provides a reference for the design and fabrication of space optical thin film diffraction lenses.