Based on the character and function of pumped storage station, a benefit evaluating indexes system is established. Considering the indexes are considerable, an hybrid model based on rough set (RS) and support vector machine(SVM) is proposed: Rough sets, as a anterior preprocessor of SVM, can find out the kernel factors influencing the safety of power supply enterprise by means of attribute reduction algorithm, and then, using them as the input vectors of SVM, the safety assessment is conducted. Experiment results compared with traditional SVM model show that the accuracy of the RS-SVM model are evidently improved.