Different from the traditional rail trains, the virtual rail trains (VRT) run on the existing roads of the city, and have been put into use in public transportation systems of many cities at home and abroad in recent years because of their higher carrying capacity compared with conventional buses. However, due to the fact that the VRT has the long body and heavy axle weight, and always tracks along local constant areas of the road in the long term, the road is prone to deformation and damage under the vehicle road, which in turn affects the quality of train operation and road dynamic performance. Aiming at actual service problems of the VRT, the current research carries out the vertical coupling dynamic analysis of the train-road system and reveals the influence of the train and road characteristic parameters on the service performance of the coupling system. Firstly, a three-dimensional dynamic model of the train is established with consideration of the vertical, pitch, and roll motions of the train, as well as inter-car articulation effects.The road dynamics model was developed based on a double-layer Kirchhoff thin plate resting on a Winkler foundation, with dynamic responses analyzed using the modal superposition method. The wheel-road interaction was characterized by the Hertzian contact model. Subsequently, the simulation on the vertical coupling dynamics of the train-road system was conducted, and the effects of the system characteristic parameters on train operation quality and road dynamic performance, including pavement thickness,Young’s modulus,vehicle speed,articulation dampling, and the grade of the road, were quantitatively analyzed using the Sperling index of the train and the root mean square value of stress of the road at the wheel contact points. A sensitivity analysis of these parameters was conducted.The results indicate that increasing pavement thickness, enhancing articulation damping, and improving the grade of the road can improve both train ride quality and road mechanical performance. However, while higher equivalent Young’s modulus of the road and increased vehicle speed enhance road mechanical performance, they degrade train ride quality. Furthermore, the grade of the road exhibits the most significant impact on system service performance, followed by operating speed and pavement thickness, whereas Young’s modulus and articulation damping have relatively minor effects.