The variation of the bus voltage in the DC micro network has a great influence on the load. In the process of regulating the DC bus voltage by the energy storage system through the bi-directional DC converter, the duty cycle will change by a wide margin, which leads to serious nonlinear problem and unstable bus voltage. To solve the problems, backstepping sliding mode variable structure control is combined with exact feedback linearization, which is applied to the bi-directional DC-DC converter. The non-minimum phase characteristics and variable structure features of the converter are solved. The method can guarantee the robustness and stability of the system under uncertain and nonlinear conditions and external disturbances. The converter state equation is analyzed firstly, and the exact feedback linearization model through coordinate transformation is deduced and then the backstepping sliding mode controller is designed. Finally, the results of simulation built by PSCAD demonstrate the validity and superiority of the proposed control scheme.