The use of reliability simulation method of repairable systems under maintenance after failure (RSS) will not be limited by the life distribution of the systems elements. Less computation is needed with this method, the computation time is short, but results are precise and determinate. The RSS method offsets the problems in the reliability simulation with the Markov and Monte-Carlo method and has practical merits in reliability engineering. In this paper, reliability assessments are applied in FYXF-03 dynamotor prime mover simulation system by using Weibull model. A useful reference is provided for making plans for equipment repair and maintenance as well as the selection of components.