To support the structural design of ceramic composite inserts， a finite element computational model for projectile penetration into composite structures was established and its reliability was validated through experiments. Using this model， the process of a 7.62 mm armor-piercing incendiary projectile penetrating a composite structure was simulated. The anti-penetration characteristics， such as target plate failure and the retention effects during projectile penetration， were analyzed. The influence of bullet velocity， ceramic thickness and fiber thickness on the anti-penetration performance of the composite structure was studied. The study shows that there is a synergistic effect between ceramics and fibers during projectile penetration. The retention effect significantly impacts the anti-penetration performance of the ceramics- the lower the bullet velocity， the longer the retention time， and the higher the percentage of bullet kinetic energy dissipation. At a bullet velocity of 500 m·s^-1， the kinetic energy dissipation during the retention period is 68.4%. The specific energy absorption of the composite structure increases with the increase of material thickness， but the penetrating specific energy absorption of the composite structure initially rises and then decreases as material thickness icreases.