The control strategy of SVG controller in outer loop based on artificial immunity arithmetic was brought forward in this paper in control technique about voltage error—reactive power in static var generator's controller in allusion to complex control object of multi-dimensional and non-linear power system.  Bionically simulating the immune process of human body in which the immunity system can bring excellent antibody for biting evil invasive antigen and maintain normal function, the control strategy takes voltage fluctuate as equivalence antigen and produces antibody for voltage stabilization. Output reference value of reactive power instruction in inner loop is gained by identifying voltage change factor in power system which corresponds to antigen mater in immunity system and setting model with fuzzy scheme for cell activation process with Mamdani fuzzy reasoning and gravitational and center fuzzy measure.  The control scheme of simulation immune mechanism brought forward in the paper is proved effective on stability of power system through the outline parameter training of the SVG simulation controller on on power system of one generator with two close loop structur the fault influence analysis about short circuit in triphase symmetry power system and comparison with parameter change by PI control manner.