The necessary conditions of all-angle polarization beam splitting effect of photonic crystal is discussed from the aspects of band structure and equal frequency surface. The conservation law of the tangential k-vector component is illustrated in the equal frequency surface. In order to theoretically verify the all-angle polarization beam splitting effect, finite-difference time-domain (FDTD) method is employed to simulate the propagation of Gauss beam in the multi-layered wavy films, getting the transmission coefficients for the TE and TM modes in the angle range from 8° to 89° respectively.