In order to analyze the track irregularity, the source of the periodical irregularity was introduced, and the simplified model of track irregularity and a levitation module model were built. Based on these models, the impact of track irregularity on the suspension was discussed. The gap fluctuation of the system was analyzed when stimulated by the different length wavelength of the track periodical irregularity. Considering the track power spectrum density in the Tangshan maglev experimental line, the sensitive wave length was pointed and some advice for the improvement of the track building was given. As the fact that many low-speed maglev tracks have been built, the way of adjusting parameters of the controller to reduce the disturbance from track periodical irregularity was studied.