In order to study the effects of windsand coupling (excitation) on the aerodynamic performance and erosion characteristics of highspeed trains at different yaw angles, based on aerodynamics theory,the Navier-Stokes equation and standard κ-ε turbulence model were used to treat the air flow continually, and the DPM model was used to discretize the sand particles. Under the conditions of 230 km/h simulation vehicle speed and 30 m/s wind speed,and under three conditions of 0°, 45° and 90° yaw angle, the aerodynamic characteristics, erosion characteristics, lateral force coefficient and drag coefficient of trains were solved by Euler-Lagrange method. The results show that the increase of yaw angle, the area of barotropic pressure gradually enlarges to the side, the eddy current gradually increases, the drag coefficient decreases and the side force coefficient increases gradually; the side force coefficient of 90° yaw angle with sand is 250 times of that of 0° yaw angle with sand, and the side force coefficient of 90° yaw angle without sand is 142 times of that of 0° yaw angle without sand; the erosion area is shifted from head to side and increased, the erosion rate is also increasing.