Abstract: The projectile penetration pre-damage granite target test was conducted, and disparate projectile initial velocity projectile penetration pre-damage granite target data was obtained. Subsequently, a projectile penetration pre-damage finite-thickness rock target numerical simulation model was established, and a comparison was made between the penetration process of the rock target damage evolution and crack expansion law. The findings indicate that the pre-damage of the rock target by the shaped charge can greatly improve the penetration ability of the 30 mm projectile on the target, and the penetration depth growth rate decreases linearly with the initial velocity of the projectile; when the 30 mm projectile penetrates the infinite granite target, the number of cracks within the pre-damaged target is fewer, the length of the cracks is shorter, the diameter of the completely damaged area around the cavity is about 1/2 of the complete target, and the width of the cracks extends to 0.3 times the target diameter. When the 30 mm projectile penetrates the 200 mm thick granite target, the diameter of the completely damaged area of the target material is also about 1/2 of the complete target, but the radial cracks extending to the target surface in the pre-damaged target are far fewer than those in the complete target, and the number of the radial cracks extending to the back of the target is similar to that in the complete target, and the extended width of the cracks in the complete and pre-damaged target is 0.5 times of the diameter of the target.