For the traditional droop control strategy of the microgrid, it is difficult to adjust the control parameters of the strategy, and it is also affected by the grid voltage and load fluctuation greatly. To address the problem, this paper presents a droop control strategy of microgrid based on the technology of the ADRC, which can maintain the stable operation of microgrid under the islanded mode and the grid-connected mode. The structure of the ADRC has strong anti-interference ability, it can suppress the fluctuation of parameters and restrain the uncertain disturbance of the grid effectively, and the design method is also simple. The simulations reveal that the control strategy can maintain the balance of the power in microgrid effectively when the load is changing, keep the microgrid voltage and frequency constant, and play a supporting role in the microgrid.