Abstract: The paper analyzed implementation principle of double closed-loop control strategy for shunt active power filter. In view of problems that PI control cannot track AC signal without static error and repetitive control has slow dynamic response speed, the paper proposed a composite control strategy based on repetitive control and PI control for current loop to improve stable tracking performance of control system of shunt active power filter by repetitive control and dynamic performance of control system of shunt active power filter by PI control. In view of problems that PI control is difficult to determine transfer function of control system of shunt active power filter and cannot online set PI parameters, the paper proposed a fuzzy PID control strategy for voltage loop to control DC voltage. Matlab/Simulink simulation result validates correctness and feasibility of the control strategy.