Abstract: In order to research the vibration mechanism of large-scale wind turbines,the parameters of blades for 2 MW wind turbine applied in the low wind speed areas are selected based on the Betz theory and calibrated based on PID control system. The integrated model including the tower,blades,hub and nacelle is established using FAST software. The dynamic responses of this 2 MW wind turbine under normal operating load case and emergency shut-down load case are analyzed. The numerical results show that the firstorder frequency of the wind turbine system is relatively lower and the vibration mainly occurs in the F-A direction. Under the normal operating load cases,the acceleration response of the wind turbine tower in the F-A direction is greatly affected by 3P and 6P excitations（P is the rated rotational frequency of the rotor）and the influence of the second-order vibration mode is obvious. The vibration of the wind turbine will be aggravated under the emergency shut down case. The acceleration response of the tower in the F-A direction is mainly affected by the first-order vibration mode,but the second-order vibration mode has a significant effect on the acceleration response in the S-S direction. The conclusions can provide a research basis for the vibration control of the full steel tower.