In order to improve the stability control of DC bus voltage in microgrid, a control scheme combining ESO and backstepping is proposed to solve the problems of nonlinearity and parameter variation in microgrid. ESO is adopted to observe the non-linearity and parameter variation of system. Backstepping method is used to design the controller, which can compensate the non-linearity and parameter variation of the system while ensuring the stability of the system. The ESO-Backstepping based control method proposed in this paper is compared with the classical PID and backstepping control methods. Simulation results show that the ESO-Backstepping based control method can realize the stability control of DC bus voltage even when the parameters of the nonlinear system change. The method is simple and effective, and has good stability and strong robustness. This work is supported by Natural Science Foundation of Hebei Province (No. F2016203006).