A novel photonic crystal fiber with high negative dispersion is proposed. The fiber core is formed by three air columns, and three air-holes with different diameters are arranged in hexagonal lattice cladding. The dispersion, mode field, nonlinearity, leakage loss and birefringence are numerically calculated based on full vector finite element method combining with anisotropic perfectly matched layers boundary condition. Results show that when the fiber structure parameters Λ,d,d1,d2 are 1.15, 0.88, 0.83, 1.14 μm, respectively, the fiber exhibits high negative dispersion in low-loss communication window C band. The negative dispersion, birefringence, leakage loss and nonlinear coefficient values are -11660 ps·km-1·nm-1,2.03×10-3,10-3 dB·km-1, 7.33 km-1·W-1 at 1.55 μm, respectively. It is shown that the optical fiber has high negative dispersion, low loss, high birefringence, low nonlinearity and good dispersion compensation ability in C band of low loss communication window, and it is expected to be used in optical communication system.