The invention discloses a multistage wind driven generator self-adaptive to wind speed and a control method thereof. The multistage wind driven generator comprises a wind power sensor, a microprocessor and a wind driven generator set, wherein the wind power sensor is used for acquiring wind speed signals of a wind field in real time and sending the acquired data to the microprocessor, the microprocessor receives the wind speed data acquired by the wind power sensor, determines the length of blades and selects corresponding wind speed models of generators according to the acquired wind speed data and sends corresponding instructions to an execution mechanism and a driving module of the wind driven generator set, and the execution mechanism and the driving module of the wind driven generator set adjust extension of the blades of the wind driven generator set and select the corresponding wind speed models of generators to work together according to the instructions from the microprocessor. The multistage wind driven generator self-adaptive to wind speed is capable of making adjustment and using the wind driven generator of a corresponding wind stage to work according to the actual wind speed, and the power supply reliability and maximum wind energy utilization of the wind driven generator are improved.