A new method to fabricate TM pass polarizers by introducing zig zag shaped proton exchanged regions adjacent to a Ti diffusion waveguide on X cut, Y propagation lithium niobate is presented. A two dimension BPM (Beam Propagation Method) has been used to analyse this new kind of polarizer. The performance of the device is shown to depend strongly on the geometrical shapes of the proton exchange regions and their distances to channel waveguide. Through optimizing the parameters, a perfect device have been realized, and a TE extinction of 23 dB has been obtained experimentally.