The yaw system of the megawatt-class wind turbine produced severe vibration in the process of work. A virtual prototype model of the yaw system was established in ADAMS based on the active yaw theory of the megawatt-class wind turbine. Vibration analysis results have shown that the first order natural frequency of torsional vibration of the yaw system is 17.6947Hz, the second order natural frequency is 55.8166Hz, the third order natural frequency is 85.1 412 Hz, and the fourth order natural frequency is 170.1823Hz. Dynamic analysis results have shown that the nacelle has to bear severe oscillation at the end of the yaw, the amplitude is as high as 0.15rad, and it will last 20s. The vibration of the yaw system can be reduced by adding a feedback control to the frame of the megawatt-class wind turbine.