A new type of photonic crystal fiber structure is designed in this paper. The fiber cladding contains six axisymmetric triangular lattices composed of air holes with different shapes, and a row of elliptical air holes with different sizes were introduced along the x-axis in the middle to achieve high birefringence, ultra-low confinement loss and large negative dispersion. The model of the photonic crystal fiber was constructed by the finite element method, based on which, the effects of the rotation angle of the two central air holes on the mode field distribution, birefringence coefficient, confinement loss and dispersion coefficient of the LP01 mode and LP11 mode were studied. The results show that the fiber has the optimal performance when the rotation angle α=90°, that is, at the wavelength of 1550nm, the LP01 mode can obtain the birefringence, confinement loss and dispersion as 3.618×10-2, 1.999×10-14dB/m and -764ps/(nm?km), respectively.