The invention provides an accident set prediction method and apparatus. The accident set prediction method comprises the steps of when electric power dispatching operation requirement is received, obtaining simulation operating data of an electric power system corresponding to the electric power dispatching operation requirement, and an electric power network topological model, a simulation dispatching operating behavior, a target line, and simulation dispatching operating behavior operation of the electric power system, and then obtaining a novel electric power network topological model; performing load flow calculation on the electric power system after the simulation dispatching operating behavior occurs through the novel electric power network topological model to generate a load flow calculation result; determining a key influence line and a key influence node corresponding to the simulation dispatching operating behavior according to a load flow initial value, a load flow rated capacity value, a load flow simulation value, a voltage initial value and a voltage simulation value; and performing prediction on an accident set corresponding to the simulation dispatching operating behavior based on the target line, the key influence line and the key influence node. By adoption of the accident set prediction method and apparatus, the evaluation calculated amount is reduced while the calculation efficiency of risk evaluation is improved.