The invention provides a dispatching method for restoring system security of an electric power system after multiple failures, and relates to the technical field of electric power systems. First a safe economic dispatching model is established and is converted to a two-stage decision model, a multi-stage robust optimization model is decomposed into a main problem and a sub problem, the main problem and sub problem are solved repeatedly, an upper bound and a lower bound of the main problem are updated, the worst scene is identified again, till a difference value of the lower bound and the upper bond of the main problem does not exceed a convergence level or reaches a maximum alternation number of items, and an optimal solution to the main problem is output. The dispatching method adopts an N-K safety criterion that satisfies power grid operation conditions, thereby enabling a calculated result to have practical guiding significance, and the thought of adopting robust optimization avoids the problem that under the N-K safety criterion, an equipment failure accident set is large in amount, and the dispatching problem cannot be solved; and a column constraint generating algorithm is adopted to decompose the multi-stage robust optimization problem into the main problem and the sub problem, thereby improving solving efficiency.