Abstract: In order to realize birefringent metasurface with simple structure and high transmittance, the generalized thin plate transition conditions was used to analyze the relationship between metasurface structure and incident field, reflection field and transmission field around it. Surface polarizability and magnetic susceptibility of dielectric space domain were utilized to describe the equivalent properties of the corresponding metasurfaces. A birefringent metasurface based on π-shaped metal structure unit was designed. By arranging 7 elements with gradient transmission phase in sequence, a metasurface with birefringence of x-polarized, y-polarized electromagnetic waves was formed. The results show that, in beam refraction and polarization splitting metasurfaces, the loss is less than -8dB. Full transmission is achieved in λ/4 wave-plate. The designed birefringent metasurface has high transmission property to electromagnetic wave incident vertically. Beam separation of x-polarized electromagnetic wave and y-polarized electromagnetic wave can be realized. The birefringence is realized. The research results have certain guiding significance for the design and implementation of high performance metasurfaces.