In order to investigate the impact resistance of the 2A12 aluminum alloy plate, blunt-nosed projectiles were launched with the impact velocity ranging from 120 m/s to 330 m/s to hit aluminum alloy target plates with a thickness of 6 mm, and the influence of the initial impact speed on the impact resistance of targets was analyzed. The ballistic limit and velocity curve of projectiles were obtained by fitting the data of the experiment. The results show that the energy absorption of the target first decreases sharply and then keeps stable with the increase of the initial velocity of the projectile. Meanwhile, the target plate mainly undergoes shear failure, and the structural deformation of the target plate decreases as the velocity of the projectile increases. Moreover, based on the ABAQUS/Explicit finite element software, the modified J-C constitutive relation and fracture criterion were used to calculate the projectile impact target model. And the failure mechanisms of targets were analyzed on the base of verifying the validity of the simulation model.It has been found that the failure mechanisms of targets are similar under different impact speeds, and the initial velocity of the projectile has little effect on the failure mechanism of target.