Abstract: To study the rotational behavior of wheelsets and the longitudinal interaction between vehicles during the braking process of metro trains, on the basis of considering the vertical and longitudinal wheel-rail contact relationships, a coupled model of vehicle and "circular track" was established based on the multi-body dynamics theory and finite element method. The effects of braking torque, inter-vehicle suspension characteristics, and axle load difference on the longitudinal interaction between vehicles under braking conditions were analyzed. The results show that during the train braking process, the front wheels are subjected to increased load while the rear wheels experience reduced load, which makes the rear wheels more prone to slipping. When the applied braking torque is within the range between the critical torques of trailers and motor cars, the longitudinal interaction effect is the most significant. The greater the difference in axle load between motor cars and trailers, the more significant the longitudinal interaction force between vehicles.