Separation method is adopted to establish the vehicle-bridge coupled vibration analysis model of the separation for vehicles,Bridges,two kinds of model,and establish the corresponding independence movement equation,according to the location of the two models in the wheel contact the harmonize condition of displacement and stress analysis by iteration method is used to solve.Based on a long-span concrete-filled steel tube(CFST)arch bridge,the effects of deck flatness and arch rib core concrete void ratio on the dynamic response are analyzed.The results show that compared with other factors,the bridge deck flatness has a great influence on the dynamic response of the bridge.At L/4 position,the effect of void ratio on dynamic response of bridge is greater than that at vault position.The influence of bridge deck flatness should be taken into account in the calculation of actual bridge impact coefficient.