Abstract: A method and system for optimizing power grid emergency load-shedding based on proliferation and reduction evolution. The method includes the steps of obtaining upper and lower limits data of allowed load-shedding amount of each load and boundary threshold data of transient security and stability constraint indexes of a power grid; and obtaining an optimal power grid emergency load-shedding scheme based on these data and an evolutionary optimization method, wherein the key of the evolutionary optimization method to work is proliferation and reduction evolution strategies. The proliferation strategy with multiple evolution search operators is proposed to generate many temporary candidate schemes. The reduction strategy of temporary candidate schemes includes two key steps, that is, pre-screening of based on a surrogate model and validation based on time-domain simulation.