In order to solve the problems of bidirectional DC-DC converter in traditional PI controlled optical storage microgrid system, such as large voltage fluctuation of DC bus, poor efficiency of charge and discharge and weak anti-interference ability, a double closed-loop control strategy based on adaptive particle swarm optimization (APSO) is designed. Firstly, the mathematical model of bidirectional DC-DC converter is established. Secondly, a double closed-loop control system with voltage loop linear active disturbance rejection control (ADRC) and current loop PI control is designed, and feedforward control is added to the voltage loop to enhance the robustness of the control system. Then, a parameter optimization system based on APSO algorithm is proposed to solve the problem that the parameters of active disturbance rejection controller are difficult to tune. The adaptive inertia weight factor is introduced in the algorithm so that the inertia weight can be dynamically adjusted in the process of particle swarm optimization to obtain better optimization results. Finally, a kind of integral of time and absolute error (ITAE) index with penalty function is designed as fitness function, and the control parameters of feedforward linear active disturbance rejection control (FF-LADRC) system are optimized autonomously. The simulation results in MATLAB show that the proposed control strategy can effectively reduce the voltage fluctuation of DC bus, improve the charge-discharge performance of energy storage system, and solve the problem of parameters setting of linear active disturbance rejection controller.