Abstract: In order to study the running security of high-speed trains under strong crosswinds, an aerodynamic model and a vehicle system dynamic model for computing the wind-induced vibration of the high-speed trains were established based on the theories of aerodynamics and multi-body system dynamics. With the models, the characteristics of crosswind aerodynamic loads acting on the train body under different wind angles, different wind speeds, and different running speeds were calculated. Then, according to the standard of Testing of High-Speed Electric Multiple Unit on Completion of Construction, the operational safety of the head car, middle car, and tail car of the train were analyzed using the operational safety indicators of the derailment coefficient, the load reduction rate, the axle lateral force, and the wheel-rail vertical force. The results show that the security of the head car is lower than the other two cars in all cases; and when the wind angle is 90° in a cross-wind situation, the security of the head car is the worst. The maximum safe wind speed decreases sharply as the train speed increases: when the train speed is 200 km/h, the maximum safe wind speed is 29.61 m/s, and when the train speed is 400 km/h, the maximum wind speed is 18.87 m/s.