In order to study the effect of semi-armor-piercing warhead's nose shapes on the projectile penetration, the process of the different nosed warheads penetrating into thick steel target are analyzed with the ANSYS/LS-DYNA software, and the effects of impact angle and attack angle on the remaining kinetic energy and deflection of the projectiles with different nose shape warheads are analyzed. The research results indicate that the penetrating performance of the oval-nosed and conical-nosed projectile are better than the blunt-nosed projectile when projectiles penetrating the thin steel target vertically, while the blunt-nosed projectile makes a greater target deformation. Impact angle and attack angle will make the projectile deflects when oblique penetrating, and the penetrating performance of oval-nosed and conical nosed projectile decrease with increasing impact angle, while blunt-nosed projectile increases first and then decreases with the larger impact angle. The little attack angle will improve the projectile's penetrating performance and have certain correction effect on the deflection angle in the process of penetration. Above conclusions are meaningful for warhead's nose shape design, determining projectile's penetrating attitude.