In order to optimize the lateral dynamic characteristics of high-speed train air springs， a high-speed train air spring with auxiliary chamber and the throttle orifice is taken as research object. The force state of rubber airbag under lateral deformation is analyzed. The frictional force and linear elastic force of rubber airbags are described by the constitutive relationship of rubber materials， and a transverse nonlinear model of the air spring is established. Based on the measured data and finite element method， the frictional force， linear elastic force and other dynamic parameters are identified. The accuracy of the model is verified by experiments， and the influencing factors of the lateral stiffness characteristics of the air spring are explored. The influence of the air spring model on the running stability and curve passability of the vehicle is calculated by importing the model into the vehicle dynamics model for joint simulation. The results show that the air spring model considering the characteristics of the rubber airbag can describe the sharp angle effect of the two ends of the stiffness hysteresis curve and it is closer to the test curve. By introducing the presented model， the lateral stability index of the high-speed train can be reduced in the dynamic calculation， and the calculation accuracy can be improved when passing the curve.