Abstract: In the light of the fact that the serious track vibration noise incidents and abnormal rail corrugation were observed in some subway lines, the research on the reason of rail corrugation was carried out. Using multi-body dynamics simulation software SIMPACK to build dynamic model of subway vehicle and track structure, the response of vehicle-track system dynamic performance and vibration characteristics of the flexible rail system was studied on rail corrugation formation. The results show that changing the track parameters such as track plate length, thickness, steel spring vertical stiffness and span, the natural frequencies of track plate all vary, but the vibration characteristics of it are basically unchanged. There is an obvious resonance phenomenon in the inner rail and track plate at 116 and 161Hz, which may cause inner rail corrugation at wavelength 132 and 95mm. The vertical bending vibration modes and frequency characteristics of the both rail sides and slab track are known to be the main reasons of the initial stages or development of rail corrugation made by the vertical vibration of track system. Which also provides a relevant thought and method about rail corrugation research problem of the steel spring floating slab track.