Bearing faults can cause changes in the air gap of doubly-fed wind turbines, generating unbalanced magnetic pull (UMP). In order to accurately reveal the bearing fault vibration characteristics of doublyfed wind turbines, a study on dynamic modeling of the outer ring fault of the bearing considering the UMP is carried out. Firstly, a bearing outer ring fault model is constructed based on the Hertz contact theory. Then, the air gap magnetic flux density of the generator rotor under normal and bearing fault conditions is derived, and the UMP acting on the generator rotor is obtained. Finally, the Runge-Kutta method is used to solve the model and the vibration response of the bearing fault is obtained. Experimental comparison analysis shows that the proposed dynamic model can effectively reveal the double impact phenomenon of the vibration signal of doubly-fed wind turbines with bearing faults, and the UMP excitation can affect the modulation characteristics of the vibration signal of wind turbine bearings outer ring faults. A new theoretical references is provided for fault diagnosis of wind turbine bearings.