To address the common issues and deficiencies associated with state-of-art static and moving train wind tunnel test, this paper devised a novel test system for the aerodynamic test of vehicles travelling across the bridges. A servo motor synchronous driving system was used along with a wireless module for the transducer in measuring aerodynamic forces on the high-speed train. The maximum speed of the train model can reach 15  m/s with an effective acquisition time of 0.7s. Besides, due to the independent arrangement between the bridge model and the test motion driving system, replacement of the bridge model can be achieved, enhancing the adaptability of the system. Based on the developed test system, a scaled model (including a steel-truss bridge and the CRH3 train system) was tested and aerodynamic characteristics of the moving train were measured and analyzed under various wind velocities, speeds of the train, and wind angles. It reveals that aerodynamic coefficients of the train measured with a static train model are different from those measured with the dynamic train model. The existence of truss bridge causes that the aerodynamic coefficients of model train vary significantly as the incoming wind velocity, speed of the train, and wind angle change. •A novel wind tunnel test system for the aerodynamic test of high speed trains traveling on the bridges is presented.•Performance of the test system is evaluated.•Comparison between static model test and moving model test is conducted.•The relationship of the aerodynamic coefficient of the train and the yaw angle is changed by the truss bridge.