Aiming to the requirements of high birefringence and multiple zero dispersion points of optic-fiber sensing and communication systems, a new type of photonic crystal fiber (PCF) is proposed. The cladding is arrayed by octagonal air holes, and two big elliptical air holes are added in inner cladding to increase the birefringence. Numeral results show that this type of PCF exhibits high birefringence with a level of 10-3 when wavelength ranges from 0.8-2 m, which fulfils the requirement of high birefringence, and two zero dispersion points are obtained after optimization. In addition, high nonlinear coefficient with a level of 10-2 m-1W-1 is obtained, which could be used in the case where the nonlinearity is highly required.