Abstract: Taking into account the geometric nonlinearity of structures, the dynamic analysis model for long-span bridges under train and wind actions is established. A long-span continuous steel trussed bridge is taken as an example to analyze the load effects of static wind and buffeting wind, the influence of wind velocity and train speed and the effect of geometric nonlinearity. The results show that the wind loads should be considered in analyzing the train and bridge system;the geometric nonlinearity affects greatly the maximum deflections of bridge, but it does not change the tendency of displacement histories;both wind velocity and train-speed have great influence on the maximum deflection of the bridge.