Wind shear and tower shadow effects can lead to forced power oscillations in direct-drive wind turbines, affecting the safe and stable operation of the system. Thus, a virtual inertia control method based on active disturbance rejection control is proposed, which optimizes the control power of the wind turbine by estimating the system disturbance power through extended state observer observation. And at the same time, using tracking differentiator to adjust the reference value of the system frequency. Simulation results show that, compared with the traditional virtual inertia control, the proposed method has better immunity to disturbances, and can more effectively observe and estimate the disturbance and compensate for it, so as to achieve the purpose of suppressing the forced oscillation of direct drive wind power grid connected system.