In order to study the redundancy,reliability and maintainability of the repairable system in a marine power station,an actual marine power station redundant system is analygeal,as well as a mathematical reliability model,which is based on Markov Process and refers to navigation condition,is established.A formula for estimating the availability and reliability of the system is derived at the same time.Then a new and practical method is provided for further redundant design of marine power station.Finally,an example to demonstrate the engineering application of automatic control system in the marine power station is given.