Depolarization splitting prism is an optical element, which coats multilayer interference film on the inclined surface of right-angle prism, gluing with another right-angle prism, forming a cube structure to let through incident P-polarized light and reflect S-polarized light. It separates the parallel and vertical polarization of a beam of light, and the transmittance ratio of P light to S light is greater than 900. It has the advantages of low stress, high spectral ratio, good imaging quality and small beam deflection angle.