Cavity expansion theory has been widely adopted by many researches in predicting penetration depth of objects under impact. The main purpose of this paper is to construct two models, each comprising different damaged zones based on the cavity expansion theory, to predict the target resistance when regarding the dual-layer ceramic/aluminum panel with finite thickness under high velocity impact. Once the target resistance obtained, the modified Bernoulli equation T-A model was adopted to predict the residual velocities of the projectile after penetrating targets with different thickness combination. The residual velocities predicted by the two models were compared with the results from ballistic test using .30” AP projectile. It was found that the accuracy of the models depends mainly on the thickness of ceramic material, that is, different model is suitable to predict different thickness combination of dual layer target considered. The damaged phenomenon after test was also investigated and analyzed. Therefore, it is suggested that the damaged models constructed in this study could be applied to predict the energy absorption of dual layer panel with different combination and thickness, as long as consideration of the cavity expansion zones is adjusted.