The invention relates to a wind and diesel microgrid frequency modulation control method with double-fed fan participation of load disturbance. The method comprises the following steps of designing an observer to carry out real-time estimation on load disturbance in a microgrid, distributing an estimation value to a double-fed fan and a diesel engine according to a proportion, and combining a traditional inertia strategy to control active output of the double-fed fan; additionally arranging a rotating speed recovery module; and according to a microgrid frequency deviation and power of the double-fed fan, designing a starting condition of the rotating speed recovery module, and after a frequency is recovered to be stable, starting the rotating speed recovery module so that a rotating speed is accelerated and is recovered to a level before frequency modulation. A frequency modulation capability of a double-fed fan participated in the microgrid is increased, a response capability of the microgrid to the load disturbance is enhanced and simultaneously a rotating speed recovery process is optimized.