In view of the problem of long replenishment period and difficulty in ship borne aircraft landing guidance equipment system, this paper studies the support of ship borne aircraft landing spare parts. Describe the key indexes and calculation method of spare parts in detail, introduce k/N(G) vote relationship to decompose complex system into series-parallel structure, establish the forecast model of critical index under different types of spare parts life distribution. The spare pats quantity makes influence on spare parts support probability, operational availability, and utilization ratio, analyze the variation principle among them, use analytical calculation method for evaluation of spare parts plan in advance, and verify the method by example. The analysis results show that the method can optimize the spare parts program, improve the completion degree and economy of the task, and provide reference for making reasonable spare parts program in advance. The method has high application value.