A type of fluorine doped dual core photonic crystal fiber polarization light splitter was designed by introducing fluorine in photonic crystal fiber silica materials and seven elliptical air holes and triangle and rectangular periodic air hole in this fiber. The structural parameters were optimized through the study of some parameters in the split structure and the performance of the split two orthogonal polarized light was analyzed.The results show that : in the optimized structure size, when the length of optical fiber is taken as the length of ultrashort 102.717 μm,it has a super separate ability which the two beams of orthogonal polarized light at the wavelength of 1.55 μm, the extinction ratio can reach 126.442 dB. Also, with 60 nm effective bandwidth.Therefore,this polarized optical splitter has an important application value in large capacity optical communication system.