Abstract: Series active power filter（SAPF） is an ideal device to solve the problem of voltage quality in distribution networks,which is a power electronic device connected in series between power grid and load to realize fast compensation of system voltage. In this paper, a finite control set model predictive control（FCS-MPC）strategy based on deadbeat outer loop control is proposed for two-level SAPF. Firstly,based on the traditional double closed-loop control,the FCS-MPC control strategy is introduced. The discrete prediction model of the system is established in the dq coordinate system,and the system delay and its compensation are analyzed to realize the rolling optimization control, which replaces the traditional current loop and omits the modulation link to reduce the complexity of the control algorithm. On this basis,in order to avoid the cross decoupling link and controller parameter tuning,the acquisition of the inverter outlet reference current is improved in the αβ coordinate system. According to the mathematical model,the deadbeat control is used to replace the traditional voltage outer loop,which reduces the coordinate transformation and further simplifies the control structure.Finally,through Matlab/Simulink and Typhoon HIL 402 semiphysical platform, the proposed control strategy and the traditional voltage and current double closed-loop control strategy are simulated and verified. The results show that the proposed control strategy has good voltage compensation effect and can effectively reduce the voltage harmonics for the grid voltage swell,sag and harmonic conditions.