A dual-core photonic crystal fiber polarization beam splitter filled with salt water in the central ellipse is designed and optimized by the full-vector finite element method. For a polarization beam splitter length of 31.1245  μm, the orthogonally polarized light with a bandwidth of 180 nm around 1.55  μm can be separated effectively and the extinction ratio (ER) is 139.88 dB. The photonic crystal fiber polarization beam splitter offers advantages such as the short length, high ER, and broadband characteristics and have large potential in optical communication.