In this study, a improved controller, aiming at “swing of plugin and takeaway of capacitor” and “operating frequently” of the traditional ninezone control method and combining the fuzzy control theory, based on fuzzy control is designed which fits for lowvoltage reactive power compensation of factories. This fuzzy controller adopts twoinput and singleoutput structure, with voltage deviation and reactive power deviation as the control variables. The reactive power compensation is the controlled variable, and the triangular membership function is selected. In order to verify the feasibility of this fuzzy controller, a reactive power compensation model based on this controller is established. The simulation results show that the proposed fuzzy controller is feasible, which solves the problem of switching vibration, improves the accuracy of the system and improves the quality of the power grid.