The paper aims at the optimization problem of UAV air-to-ground missile weapon system. The AHP method is adapted. According to the mission and typical combat mission of close air support in system confrontation, and consider the role of the weapon system in the system. the effectiveness evaluation index system of unmanned airborne weapon system is constructed based on the evaluation criteria layer of detection ability, shoot range, multi-target strike capability, strike accuracy and ability to adapt to complex environment. The hierarchical structure model, judgment matrix and index weight are established. The operation effectiveness of three missile weapon system schemes is quantitatively evaluated. The results show that the performance indexes of different system schemes to complete typical tasks can be given quantitatively by this method. Using compound guidance and multifunctional damage scheme can significantly improve the effectiveness of unmanned airborne weapon system. It provides a theoretical basis and support for the operational use and structure of the weapon system.