Aiming at the characteristics of complex structure, long maintenance time and high maintenance cost in the maintenance process of multi-component system, the dynamic opportunity maintenance strategy of multi-component series system was proposed. Four factors were considered in the strategy: preventive maintenance duration, minor repair duration, structural dependence and economic dependence. Firstly, single component was used as a research object. The optimal maintenance period of the component layer was determined, and the system trial maintenance plan was formulated. Then, based on a trail plan and considering the structural dependence and economic dependence, the system-level maintenance optimization model was established with the maximum cost saving as the optimization goal. The rolling plan was applied to achieve dynamic updates of the maintenance plans. Through arithmetic example, this proposed policy is proved to be effective and necessary.