Abstract: An analysis method for the function effect of base equipment in multi-equipment cooperating battle system was studied to planning fire in system-of-systems combat. Based on the analytic hierarchy process (AHP), an effect model was developed to analyze the effect of base equipment on the whole function of multi-equipment cooperating battle system, and its solving method was provided. Taking a foreign air defense system of fleet as example, consisting of eight warships in three different types, the effect of every warship on the whole air defense capacity of fleet was analyzed separately, and the effect of the whole or partial damage of related equipment on the whole function of air defense system in fleet was obtained. Based these, the most important vessel and equipment for the whole air defense capacity of fleet was found. Results show the method is useful for fire planning in system-of-systems combat.