Allocation of fleet’s spare parts is rarely studied due to its complexity.However,this task is extremely important because the warship’s service level highly relies on the maintenance logistics’ level.In this study,the readiness ratio is proposed as a critical index in measuring the system’s reliability.A well-established mathematical model adopting the optimization method of spare part allocation is also introduced.The objective is to minimize the number of each spare part while satisfying the fleet’s system reliability.The fault tree analysis (FTA) is applied to analyze the system’s failure logic and stratify the units on ship.As a result,the strategy of spare part sharing can be introduced in detail.The solution algorithm is developed,and the simulation experiments to obtain the key parameters are conducted.The proposed model and algorithm are applied to an actual fleet of two warships,and results show that the method above is feasible and can be directly applied into practice.