Abstract: In view of the problem of insufficient self-adaptive adjustment ability of the traditional control strategy of electric spring,this paper improves the traditional control strategy. Considering the variation of system operation conditions or parameters,especially the influence of possible variation of non-critical load resistance during the operation of the system on the voltage regulation performance of electric spring and the limitations of conventional fuzzy control, a fuzzy proportional-integral（PI） selfadaptive control strategy in variable universe is proposed. This strategy timely adjusts the fuzzy universe according to the values of input errors, to obtain better control effect. Combining the respective advantages of the functional scaling factor and the fuzzy inference scaling factor, the scaling factors of the input universe and the output universe are designed separately, which improves the control accuracy. Simulation analysis shows that, compared with the existing control strategies, the proposed control strategy further improves the system stability and enhances the self-adaptive adjustment capability of electric spring.