In order to study the vehiclebridge coupling vibration of multigirders highway bridges, a method based on interpolation function of rectangular thin plate element was proposed. In this method, the contact points between the wheels and the bridge surface were utilized as the boundary condition, which divide the vehiclebridge coupling system into two subsystems. The equations of motion of the vehicle were established by the virtual work principle, while those of the bridge were obtained by the finite element method. Based on the displacement coordination condition between the wheels and the bridge surface and the balanced relationship of axle interaction force, the relationship between the axle contact point and the node of the bridge and the distribution of axle interaction forces were achieved by the rectangular thin plate shape function. The dynamic responses were obtained by iteratively solving the equations of motion of the vehicle and bridge. According to the computational procedure of this method, a program for dynamic analysis of the vehiclebridge coupling system was compiled, and its feasibility was verified by numerical examples. The results show that the proposed method can predict dynamic responses of the vehiclebridge coupling system with higher accuracy, and the method has wide applicability, which provides a new view for the vehiclebridge coupling vibration analysis of multigirder bridges.