Abstract: Based on wheel-on-track rolling contact model which is established by explicit finite element method, the stress variation about the wheel of 110-meter aperture radio telescope passing through the welding joint is analyzed. When modeling, not only the material difference at the welding joint, but also the influence of the flatness and friction coefficient at the track welding joint are considered. According to the model, when the wheel passing through the welding joint, the transient response of the force between wheel and track is analyzed. The hierarchical subdivision technology is used to preprocess the wheel-on-track model, and the results of static analysis show that the model has high precision. The transient analysis results show that, the Mises stress is increased by about 20% due to the track flatness, which may bring some hidden danger to the track's long-term reliable service. Therefore, it is necessary to inspection and maintenance the status of the track regularly to ensure the long-term reliable service characteristics of the track.