A novel octagonal duel-core photonic crystal fiber based on tellurite glass was proposed.Using the Full-vector finite Element Method (FEM) and coupled-mode theory,impacts of structural parameters on characteristics of the coupling was analyzed.The results show that the coupling length decreases significantly as the value of hole-pitch decreases,but the relative coupling length changes slightly as the value of hole-pitch decreases;the coupling length increases slightly as the value of air hole diameter increases,the relative coupling length increases significantly as the value of air hole diameter increases;the coupling length increases slightly as the value of ellipticity increases,the relative coupling length increases significantly as the value of ellipticity increases.The performance of the design polarization splitters was desired when the relative coupling length is 1.Then a kind of polarization splitters based on the proposed dual-core PCF was obtained.The two polarized lights are separated entirely with 139 μm fiber,simultaneously the polarized light extinction ratio is -53.46 dB at the wavelength of 1.55 μm.Besides,the bandwidth is over 120 nm when the extinction ratio is less than -20 dB,which exhibited high performance of splitting one light into two orthogonal polarization states comparing to the other duel-core polarization splitter with highly extinction ratio and short length.