Based on the public intelligence information and performance parameters of US ground-based midcourse defense system， a method of threat control zone of ballistic missile defense is proposed. An analysis model of threat control zone of US ground-based midcourse defense is constructed. The threat control zone of US ground-based midcourse defense in the two cases of GBI in flight keeping line-of-sight communication with base and supported by multiple IFICS data terminals （IDT） is simulated， which will contribute to understand the capabilities of US ground-based midcourse defense more thoroughly and accurately.

Based on the development of the U.S. ground-based midcourse defense system and public intelligence information， the early warning and tracking identification capabilities， protection zone， missile single-shot kill probability， multiple targets capability and ability level to deal with threat targets are quantitatively analyzed or qualitatively assessed applying systems engineering methods with the industrial foundation and technical level of US ballistic missile defense， which will contribute to understand the capabilities of the U.S. ground-based midcourse defense more thoroughly and accurately.

According to the development of US Ballistic Missile Defense System （BMDS） and the operational concept of kill chain and kill net， the concept and their closure of the information chain， time chain， energy chain， recognition chain， precision chain within the kill chain of US BMDS are analysed with the typical example of U.S. ground-based midcaurse defense system against the North Korea’s intercontinental ballistic missile attacking American mainland. The kill net and its comprehensive defense capability of ballistic missile defense for American mainland and overseas theater are analysed with the typical examples.