A system based on Mach-Zehnder interferometer and supercontinuum white light, which is used for ultra-broadband and high precision dispersion measurement of photonic crystal fiber, is designed and constructed by considering the shortcomings of all the available methods. A photonic crystal fiber (PCF) with core diameter of 5 μm, hole diameter of 3.54 μm and pitch of 5.52 μm, is measured respectively. The measured dispersion coefficients are well in agreement with the simulation results, and the difference between the zero dispersion wavelengths is smaller than 50 nm, which show good perfermance of the method and the experimental system.