In response to the phenomenon of bending and torsional coupling of the upper structure of a curved bridge under vehicle load, the displacement and stress responses of the cross-section at the midspan of the curved bridge under the combined action of the vehicle and the bridge were analyzed and studied using ANSYS finite element software and UM dynamic software The results show that the displacement and stress responses reach their peak values when the vehicle travels to the midspan of the span, and reach the opposite peak values when it travels to the midspan of the adjacent span. The radial displacement is proportional to the vehicle speed, and the trend of other displacements and stress responses other than the radial displacement remains unchanged, while the peak values of the responses are not proportional to the speed. The lateral load causes the radial displacement at the midspan to shift in the opposite direction of the load, and the overall trend of the other displacements and stress responses is basically unaffected by the lateral load. The increase in the roughness grade of the road surface causes an increase in the amplitude of the fluctuations of the upper structure response.