Abstract: The wide application of energy storage system helps to improve the absorption capacity of renewable energy uhder high penetration rate. For restraining output fluctuations of renewable energy source and responding frequent changes in flow direction of energy storage system,a control strategy of bidirectional DC-DC converter in energy storage system based on active disturbance rejection control（ADRC）and model predictive control（MPC）is proposed. The current inner loop adopts a MPC method,which improves the response speed and does not require parameter tuning. The voltage outer loop adopts a reduced-order control strategy based on ADRC,which reduces the order of control object in the high frequency band and reduces the complexity of the controller. Simulation and experiment show that when inductor current and output voltage reference value change suddenly,system can quickly adjust to the given value within 0.2 ms and 30 ms respectively;when load and power supply voltage change suddenly,system can recover stability within20 ms. The results verify that the method proposed in this paper has characteristics of fast response,small overshoot and fluctuation range in the adjustment process,which is superior to PI+MPC strategy.