The invention discloses a method for evaluating enforceability of a duty strategy of a power system security and stability control device, and a control strategy relation model of the security and stability control device is established. Determining a duty policy for each anticipated failure or overload monitoring device defended in the security and stability control device; Determining an allowable state of each candidate control measure; Determining the actual control amount of the on-duty strategy of each predicted failure or overload monitoring device defended by each set of control devices and the corresponding set of control measures to be executed; According to whether the control device or the execution device adopts two sets of configurations in the same plant or station, the required control quantity and the actual control quantity of each set of predicted failure or overload monitoring equipment on duty strategy defended by each set of devices are merged and handled; An enforceable state of each type of control measure of the on-duty strategy is determined, and on this basis an enforceable state of the on-duty strategy of each anticipated failure or overload monitoring device is determined. The invention improves the intelligent level of the on-line monitoring and early warning of the power system security and stability control device.