In order to obtain photonic crystal fiber with high birefringence and low loss, an elliptic double core photonic crystal fiber with triangular lattice arrangement is designed. The relations between the air hole pitch of the fiber and birefringence, non-linearity characteristic, mode field area, confinement loss and dispersion is studied by using the full vector finite element method. The results show that the birefringence of the fundamental mode of the fiber reaches 0.04343 at the wavelength of 1.55 μm, and the nonlinear coefficients in X and Y polarization directions are 48.832 w -1.km-1 and 46.286 w-1.km-1 respectively. At the same time, the confinement loss in the X direction is as low as 8.242 ×10-9 dB/km. In the wavelength range of 0.85～1.8 μm, the disper-sion is normal negative dispersion.