The aerodynamic asymmetrical fault plays an important role in the safe and stable operation of wind turbines. Traditional diagnosis technologies based on vibration monitoring require a large number of sensors mounted on wind turbines, resulting in high costs and poor reliability. In recent years, experiments have used diagnosis technologies based on the electrical signals, but cannot provide theoretical understanding of the diagnosis technologies. In recent years, experiments have been conducted using diagnosis technologies based on electrical signals, but they cannot provide theory for understanding the diagnosis technologies.This paper studies wind turbine tower vibration and the aerodynamic coupling rule under aerodynamic asymmetry. Then, the electric power fluctuation reasons are elaborated to the vibration of the tower. Finally, the wind turbine model is established under the fault to obtain the tower vibration signal and generator power signal, which have detected the first frequency of the rotor under the fault.The simulation results are consistent with the experimental results.