Abstract: The influences of wind barriers on the aerodynamic effects of a train-bridge system and running safety of a high-speed train on a bridge are analyzed on the basis of a dynamic analysis model for a wind-train-bridge system. Taking a 16 m span simply-supported U-girder bridge located in Baili wind aera on Lanzhou-Xinjiang new high-speed railway as an engineering background, the three-component force coefficients of the train vechicle and the bridge girder were measured with and without barriers by wind tunnel tests. The whole histories of a train passing through the bridge subjected to strong cross winds are simulated, from which the threshold curve of train speed and wind velocity for ensuring the running safety of the train on the bridge is proposed. The numerical results show that the train speed on the bridge should be limited as the wind velocity is over 15 m/s in the case without the wind barriers, whereas with the designed wind barriers, the train can still run safely at 260 km/h on the U-girder bridge even when the wind velocity reaches 40 m/s.