In order to obtain a short-length polarizing beam splitter with a high extinction ratio, a hexagonal dual-core photonic crystal fiber(PCF) polarizing beam splitter based on SiO2 is designed. The polarizing beam splitting is performed using the full vector finite element method and mode coupling theory. The coupling length, coupling length ratio, extinction ratio and bandwidth of the filter were numerically analyzed. The research results show that at a wavelength of 1.55 μm, the length of the polarization beam splitter is 103.05 μm, the extinction ratio is as high as 117.78 dB, and the bandwidth of the extinction ratio is greater than 20 dB is 100 nm, covering the entire C-band and most of the S and L bands.