Abstract: Aiming at the optimization of a maintenance strategy for multi-component systems, modeling methods and algorithms are studied based on failure and economic interactions. The model of discount criterion for multi-component systems is established. The optimal equation of maintenance cost is obtained and transformed into a linear programming problem. The aggregation algorithm is applied to reduce the scale of the linear programming problem and the iterative algorithm is applied to get optimal solutions. Finally,the influence that the degree of failure exerts on the total cost of the discount and the optimal maintenance strategy are illustrated by numerical cases. The influence of the cost parameters on the maintenance strategy is discussed. Experimental results show that the iterative algorithm effectively improves computing speed and reduces memory consumption.