This paper is going to study the maintenance strategy optimization of repairable equipment in the imperfect maintenance mode. By introducing age reduction factor, repairable equipment can effectively describe the effects of imperfect maintenance. For the current age reduction factor is usually given by industry experts without a clear quantitative calculation formula, this paper offers an improved formula on the basis of its definition. The new formula takes not only traditional factors like repair times,costs, etc. but also subjective factors like equipment importance into account. Based on this and NSGA II(the second generation of non-dominated sorting genetic algorithm), the traditional scheduling maintenance strategy tries to solve its model whose objective function includes the maximum reliability, maximum availability, minimum total costs. Finally, by taking the radio relay equipment of mobile communication vehicle as an example to calculate and demonstrate, its validity was proved.