Abstract: On the basis of the existing substation microcomputer anti-misoperation system, the states of secondary devices are collected by non-electricity quantity mode, the secondary device model is extended, the anti-misoperation rules of secondary devices are proposed, and the anti-misoperation logics between primary devices and secondary devices, and between secondary devices are established. The anti-misoperation algorithm of secondary devices based on expert knowledge base is designed to realize the anti-misoperation locking function of primary and secondary devices. The maintenance section of secondary devices is established, and the deployment of safety isolation measures and prevention and control of maintenance and operation process are carried out through operation ticket, lock out and tag out, so as to realize the automatic safety control in the whole process of maintenance operation. Field practice shows that the risk management and control system for anti-misoperation of secondary devices improves the anti-misoperation level of primary and secondary devices and the safety risk management and control ability of maintenance operation, and ensures the safety of equipment operation in power grid.