A variable spacing fuzzy mutual control strategy with self-adjusting factor is proposed in the whole field, which aims at the given control object of unified power flow controller in this paper. This strategy is applied to control system of unified power flow controller so as to reduce the complexity of many adjustments factor seeking superiority and overcome the conflict of equal spacing fuzzy quantification between improving stable state precision and the dynamic performance in the whole system as well as the shortcoming that decoupled control is difficult to precise decoupling when the running point of power line is uncertain. Simulation study is applied to a single generator infinity system and simulation result indicates that line power flow, node voltage and direct current side capacitor voltage of unified power flow controller are effectively controlled with quick response, small over modulation, high control precision and strong robustness in the designed control system.