The invention relates to a photonic crystal fiber and a preparation method thereof, The photonic crystal fiber comprises an optical fiber body, a fiber core is arranged in the center of the optical fiber body, a plurality of continuously rotating air holes are arranged in the optical fiber body, the air holes are spiral, the rotating directions of the air holes are the same, and the air holes arearranged in a symmetric array around the hexagon of the fiber core on any radial cross section of the optical fiber body. The photonic crystal fiber has a better circular birefringence effect, has a better temperature anti-jamming capability, and can provide a better sensing effect.