Based on the threedimensional unsteady incompressible NavierStokes equation and the turbulent model of ktwo equations, and by using the CDF software FLUENT, this paper simulated numerically the aerodynamic characteristics of sound barriers on embankment when the train passes, and studied the changes of pressure fluctuation on sound barrier. The numerical calculation model of a highspeed train passing by the sound barrier on embankment was established, and the aerodynamic pressures on sound barrier were simulated by using the sliding mesh technology in FLUENT, considering the speeds of train 200km/h, 250km/h, 300km/h and 350km/h, respectively. The magnitude and variation of aerodynamic forces on sound barrier were obtained, and the characteristics of aerodynamic pressure along the vertical and longitude directions of the sound barrier were analyzed. The relationship between the amplitude of the sound barrier pressure and train’s speed was fitted. The structural analysis model of sound barrier was established by ANSYS Workbench, and then the aerodynamic pressure was loaded to the sound barrier and the modal analysis and transient dynamic response were researched.