Abstract: Wind, vehicle and bridge can be regarded as a coupled vibration system. Based on the novel three-dimensional dynamic model of the wind-vehicle-bridge system, the dynamic responses of vehicles and bridge of a long-span road-rail suspension bridge under wind action were analyzed to demonstrate the effects of wind speed, vehicle speed and the layout of track system using the self-developed software, BANSYS (Bridge Analysis System). Based on the reasonable assessment index, the train running safety and passenger riding comfort across the bridge were studied and the resistant-wind criterion of running train was obtained: the trains can safely pass the bridge with the design speed (80 km/h) when the wind speed is lower than 20 m/s; or no more than 60 km/h when the wind speed is 20~25 m/s; the rail traffic must be closed when the wind speed is above 25 m/s.