The invention discloses a power transmission and transformation equipment maintenance plan decision method under the power grid emergency state, belonging to the technical field of power system automation. The method includes calculating the maintenance task completion delay loss time correlation factor based on the recovery scheme and target; calculating the maintenance task cost performance through the combination with the maintenance task resource demand information; calculating the sorting factor of the maintenance task by applying the comprehensive probability of fault regeneration of maintenance task related equipment; and determining the maintenance task plan by taking the maintenance task sorting factor as the main body and by taking the principle that the maintenance task resource demand is closest to the residual available resource as an auxiliary. The method provided can improve the utilization efficiency of the maintenance resources under the power grid emergency state, promote the smooth implementation of the recovery pre-arranging plan, provide technical support, improve the handling capability under the power grid emergency state, and reduce the power loss.