Abstract: In order to obtain photonic crystal fibers with good dispersion characteristics, by the finite element method, the theoretical analysis and experimental verification were carried out, and the effective index of refraction and dispersion coefficient with the change of wavelength were obtained. According to the analysis results, when the hole diameter d=1.6μm and the hole spacing Λ=2μm, the dispersion flatness is better in the 1.2μm~2.1μm band and the dispersion coefficient is 108.20ps/(nm·km) at the wavelength of 1550nm. Based on this structure, effect of different filling modes and filling material on the dispersion characteristics was studied. The results show that better dispersion characteristics are obtained for the "十" shape filling method, and that when ordinary alcohol is used as filling material, the dispersion coefficient at the wavelength of 1550nm can be reduced to 20.39ps/(nm·km), which is close to that of a G.652 single mode fiber at 1550nm. This result is helpful for research in the optical communication field.