At present, the deterioration of power quality caused by the access of distributed power sources and other types of power electronic load in distribution network is serious, and D-STATCOM can effectively solve it. In order to further improve the dynamic response ability and compensation effect of D-STATCOM, it is necessary to improve its control strategy. Firstly, the mathematical model of the three-phase four wire D-STATCOM in the stationary phase of the abg coordinate system is established by taking the grid side current and the DC bus voltage of D-STATCOM as the state variables. Then, according to the particularity of distribution network with distributed generation power quality: power fluctuation, unbalanced and nonlinear. The improved control strategy is used to design the current loop controller, and the improved three-phase four wire D-STATCOM has the characteristics of short dynamic response time, high steady-state accuracy and small amount of calculation. Finally, the feasibility of the proposed control strategy is verified by experiments.