Aiming at grid-side converter control problem of wind turbine under unbalanced grid voltage, a vector control method based on proportional integral resonance (PIR) controller is proposed. The paper establishes a mathematical model of doubly-fed wind generators and their grid-side converters under unbalanced grid voltage conditions, and analyzes its working principle and control relationships. The article introduces the working principle of the resonant controller, and establishes its mathematical model, designs the resonant controller’s parameters. And the simulations are made in MATLAB. A 6 MW doubly-fed motor model was built in the MATLAB simulation platform, which verified that the resonant controller can accurately control the grid-side converter tracking grid voltage, and is helpful for the smooth operation of the doubly-fed motor.