The reliability and risk analysis of the safe operation of high-speed trains under stochastic winds is studied based on the reliability theory. First, the numerical simulation of the stochastic winds is established, and the unsteady aerodynamic load calculation methods for high speed trains under stochastic winds are studied. Then the multi-body system dynamics model of a high-speed train is established, the probability of failure and its sensitivity with respect to mean and standard deviation of high-speed trains running at different velocities under different stochastic winds are calculated. Moreover, the formula for the extreme values and extreme points of global reliability sensitivity are derived and the probabilistic characteristic wind curve is obtained in this paper. The results show that, the probability of failure increases with the vehicle or wind speed increasing. When the vehicle speed is fixed, sensitivity of the probability of failure with respect to mean has a maximum value, and sensitivity of the probability of failure with respect to standard deviation has a maximum value as well as a minimum value. The operation security domain computed by the traditional deterministic method is too conservative, and a more reasonable security domain curve can be obtained using the method based on the reliability theory.