The invention relates to a standby electrical network accident recovery capacity adequacy evaluation method. The method comprises steps that, 1), electrical network models of a local area electrical network and an adjacent area outer electrical network are respectively acquired; 2), a power distribution coefficient in the local area electrical network and a power adjustment distribution coefficient of the adjacent area outer electrical network are respectively calculated; 3), the power adjustment distribution coefficient is taken as a system power generation adjustment step; 4), for standby accident recovery capacities of the local area electrical network and the adjacent area outer electrical network, electrical network generator output can be adjusted according to the step; 5), a power value of each electrical power node in a standby capacity adequacy evaluation calculation model can be acquired through trend calculation, and power deviation values of first and end nodes of a power transmission section middle connection wire can be acquired; and 6), whether the power transmission section trend recovers to a level before a fault is determined through the standby capacity adequacy evaluation calculation model. Compared with the prior art, the method has an advantage of simple and accurate calculation.