Aiming at the maintenance decision based on insufficient monitored degeneration informationand considering the actual situation of missileswe made study on missile components by using Wiener model to describe their degeneration process.Bayes method was used to establish a renewable remaining life prediction model on the basis of historical life data and online monitored degeneration information.Particle swarm arithmetic was used to solve the maximum likelihood functionand a priori estimate of lifetime distribution parameter was obtained.The posteriori estimate was obtained by using recursive method.Thereforethe remaining life distribution was updated.Thenthe maintenance decision models were built up based on usability and economic objectives respectively.And a multiobjective model was established by using interaction method with integration of the two objectives.The model was used in a laser gyroscopethe critical component of the missile inertial navigation systemand realized the optimized multiobjective maintenance decision.