The invention provides a method and a system for optimizing a starting sequence of power generators. The method comprises the steps as follows: determining father node information of nodes in shortest weighted paths and weight values of the shortest weighted paths; determining comprehensive priority indexes of target power generators respectively according to the weight values and the starting capacity and the climbing rates of the target power generators; taking the target power generator with the minimal comprehensive priority index as a starting target; determining the shortest weighted path of the starting target through the father node information; solving a system comprising the starting target and the shortest weighted path corresponding to the starting target as well as an electric network by the primal-dual interior point optimal power flow; judging if the optimal power flow of the system is converged; and if so, incorporating the starting target and the shortest weighted path corresponding to the starting target into the electric network. According to the method, the optimal power transmission path is prevented from being repeatedly acquired, and the efficiency of acquiring the starting sequence of the power generators after blackout is greatly improved.