Purpose <p>In this paper, an analytical model is proposed for the multi-span continuous bridge and train coupling system, which is very useful to quickly obtain the dynamic response of the system, and then facilitates the establishment of the dynamic parameters of the railway bridge at an early design stage.</p> Methods <p>Firstly, by applying the boundary and match conditions of the multi-span continuous bridge, the characteristic equation for the bridge is derived. Then, the analytical mode shapes of the bridge are obtained, and the orthogonal relationship of the mode shapes is established. According to the interaction force between the bridge and the train, the analytical dynamic model of the vehicle-bridge coupling system described by ordinary differential equations (ODEs) can be obtained by using the analytical mode shapes of the bridge.</p> Results <p>Based on the dynamic equations in this model, the vibration responses of the bridge caused by the high-speed train are calculated for different span lengths. The simulation results show that the span length has a great influence on the vibration responses of the bridge caused by the high-speed train.</p>