In order to prevent the occurrence of large-scale blackouts，analyzing the development mechanism ofdomestic and foreign several blackouts，studying the measures to prevent large-scale blackouts on intelligent substa-tion. By improving backup protection existed，determining the electrical difference between fault and overload，anddetermined the algorithm of overload recognition，then using the features of information sharing ion intelligent sub-station to complete load shedding with automatic equipment. With the analysis of PSCAD/MATLAB，test the measure correctly and effectively，and discusses the application of advanced features on intelligent substation to preventblackouts，determine The core logic nodes and the way of the realization intelligent substation，has a great signifi-cance for the promotion of the development of intelligent substation.