Abstract: In order to simplify the structure of the birefringence dual frequency laser in which a birefringence element(a quart crystal or an artificial stress plate)is settled to achieve frequency difference(FD)according to frequency splitting theory,improve the convenience of adjustment,and improve stability of FD,a novel structure of dual frequency laser is constructed,in which the FD is produced by the complex multilayer birefringent film. Different layers of the multilayer film perform different functions for the whole film system of sandwich structure. Utilizing both the transverse Zeeman effect and intra-cavity birefringence effect in a He-Ne laser,about 7.5MHz of FD is achieved in experiments.