The principles implied in the process of EFP(explosively formed projectile) impacting the plate covered explosive and the ceramic composite armor have provided the evidence for calculating the residual velocity of EFP(explosive formed projectile) impacting a new integrated armor, and a calculation model has been induced. It is proved that although the integrated armor and the ceramic composite armor have the same facial density, the protective performance of integrated armor is better than the ceramic composite armor. This calculation model can be used in the design of integrated armor. Meanwhile, according to this model the goal of EFP resistance armor can be established.