Abstract: An analytical model for the penetration of a following kinetic energy projectile into concrete targets with pre-drilled cavities is developed based on a modification of cavity expansion theory.It is analyzed that the penetration performance is affected by different pre-drilled radius.The law of penetration a following projectile is studied.It shows that the depth of crater formed by a precursor shaped charge has limited influence on the enhancement in penetration performance.However,the diameter of crater influences it significantly.The model is validated with experiment results.