Abstract: In order to ensure the rationality of scheduling operation sequence in the power grid dispatching operation ticket system, a kind of mechanism based on the risk theory is put forward to search for the optimal power supply path when load needs to be transferred. The mechanism adopts the depth first search strategy in analyzing the power network topology structure to search for load transfer paths. To generate feasible power supply schemes, it combines the heuristic pruning technique to rule out invalid load transfer paths according to the economy and safety principle of power grid. On the basis of comprehensive static security risk index, which considers the probability of cascading failure of power grid, the optimal power supply path will be selected from the feasible schemes.Examples demonstrate the rationality of the proposed mechanism.