Based on the united idea of geometry optics and phase modulation of binary optics, a prism array is used to change four incident beams, which have 45 degree gradient with horizontal axes, into parallel beams, and then the beams transit the two-dimension pure phase element which is designed by couterchanged two one-dimension phase. Through the lens, the uniform irradiance on the ICF targets which are superposed by four beams is achieved.