The invention relates to an electricity demand-satisfied power grid project operation benefit evaluation method and system. The method comprises the following steps of: acquiring to-be-evaluated practical operation electricity data; evaluating the efficiency of an electricity demand-satisfied power grid project according to the acquired electricity data; evaluating an effect of the electricity demand-satisfied power grid project according to the acquired electricity data; and evaluating the safety of the electricity demand-satisfied power grid project according to the acquired electricity data. According to the method and system, the operation effects of electricity demand-satisfied power grid projects are comprehensively evaluated by comprehensively considering the project efficiency, project effect and project safety.