A new double layered complementary frequency selective surface (FSS) based on square ring is proposed. One side of the FSS is an improved type of square ring metal patch, and the other side is a complementary metal screen. The transmission characteristics of the proposed FSS are studied. Meanwhile, the incident wave with different incident angles or with different polarization modes are analyzed respectively. Numerical simulation and actual measurements have shown that the new frequency selective surface has improved stability for different incident directions and polarizations, and it will provide a valuable reference for the design of FSS complementary screen.