The penetration rate of distributed power in the microgrid was higher and higher, and the impact of its intermittence on the stability of the system voltage could not be ignored. Electric spring (ES) was a new type of voltage control device that could effectively suppress voltage fluctuations across critical loads (CLs). In order to reduce the influence of load changes on the voltage regulation capability of ES, an adaptive control strategy of ES considering variation of noncritical load (NCL) was proposed. The topological structure of ES and the theoretical analysis of restricting operation conditions were introduced. The voltage sag was detected by the method of changing αβcoordinate system to determine whether the ES was put into the system. After calculating the compensating voltage with reference voltage calculation module, the error relative to the actual value was input into the PI controller. The PI control parameters were dynamically adjusted by artificial fish swarm algorithm (AFSA) to alleviate the influence of NCL variation on the basis of ensuring the stability of CL voltage. The simulation results showed that the proposed control strategy could effectively alleviate the voltage instability caused by load changes under different operating conditions on the basis of ensuring CL voltage stability.