There is a problem of bus voltage fluctuation caused by uncertain factors such as power fluctuation of the distributed new energy system and load frequent switching of load side in bipolar DC microgrid. Thus a dual-closed-loop improved high-order sliding mode active disturbance rejection control (ADRC) strategy is proposed for a bipolar hybrid energy storage DC microgrid based on wind-PV complementarity. First, the control system is fitted to a first-order system model and transformed into an ADRC paradigm. Secondly, an improved super torque sliding mode controller is designed to replace the linear controller in the traditional ADRC. A cascade finite time extended state observer (CFT-ESO) with fast convergence is introduced to replace the linear extended state observer. This can not only suppress the chattering using high-order sliding mode control algorithm and but also improve the estimation accuracy of the lumped disturbance of the system, thereby improving the dynamic response process and disturbance rejection performance of the system by taking advantage of thenonlinear control strategy. Then, the stability of the control system is proved by Lyapunov theory. Finally, Matlab/Simulink simulation software and an experimental platform are used to verify three different control strategies. The experiments show that the proposed control can both resist the disturbance well and improve the transient performance of the system.