It is the key to ensure the sustainable operation of intelligent substation to accurately predict the effective life of centralized protection measurement and control device in intelligent substation. A life prediction method based on cloud model and Markov chain is proposed. The initial state probability distribution vector is constructed by using the operation state data of the centralized protection measurement and control device and the membership function of the cloud model, then the state transition probability matrix is obtained according to the Markov chain principle, and the effective life of the protection device is predicted by the reliability criterion. The result of calculation example shows that the method can scientifically predict the effective life of the centralized protection measuring and controlling device, and can provide guidance for the status maintenance of the intelligent substation device.