The best defensive formation against incoming missiles is based on the greatest detectable area scale, and is measured by ＂anti-saturated-attack capability＂. Intercepted batches from each direction can be limited by two factors： the first one is the distance from the command ship to the incoming missile when the incoming missile is found, the greater the distance, the more adequate the defense readiness and the greater the intercepting batch; the second is the distance between frigate and incoming missile trajectory, generally the smaller the intercepting distance, the shorter the time of single intercept and the great the intercept batch. The direction of the least intercepting batch with probability 1 is defined the most dangerous direction. Each direction＇s batches can be intercepted of initial formation varies a lot by calculating, through ＂peak load shifting＂ way to balance and optimize. Taking intercepted batch expectations as the standard, the most dangerous direction and the batches probability 1 can be intercepted are same. With the support of AWACS, formation can make an earlier interception to launching missiles far from the command ship 148.4 Km on the most dangerous direction, so that the anti-saturated-attack capability is increased. However, due to the limit of air defense missile＇s range, the information provided by AWACS underutilized. Now the main contradiction limiting the formation＇s anti-saturated-attack capability turns to the range of anti-aircraft missiles.