Development of American air-based anti-missile interception weapon system is summarized systematically in this paper. The development motivation of this system is analyzed from operational effectiveness,using flexibility and development feasibility. The development process is analyzed from the point of view that the development direction is determined by technology foundation and limiting factors. The development law and characteristics are analyzed from the aspects of technology direction,capability requirement and key technology. From the demand and direction of development and key technologies,the enlightenment on the development of space-based anti-missile interception system in America is put forward,which can provide basis and reference for the development of airborne anti-missile interception weapons.