Abstract: To overcome the deficiency of current model, the issue of building new model to calculate aircraft survivability in active self-defense is necessarily to be researched. First, the aircraft survivability is analyzed from the view of combination of attack and defense. Then, considering the fact that the relationship between the aircraft and threats is of constraint each other, the active self-defense ability of aircraft could be defined as a weapon platform. Finally, a new model of computing survivability related to the active self-defense ability is established in the condition of positive correlation relationship between weapon's active self-defense ability and its survival state. An example has been implemented to analyze the influence of factors on aircraft survivability and the results validate the correctness and rationality of the proposed model. It is concluded that, in consideration of aircraft's active self-defense ability, the aircraft survivability is boosted noticeable if the threat system is settled, while the trend and degree of the boost are relevant to aircraft's active self-defense ability and threat targets' vulnerability.