In order to study the penetration characteristics of non-circular section warhead, the numerical simulation of circular section and non-circular section warhead penetrating into double-layer steel plate was carried out, and the numerical simulation results were analyzed. Under the penetration conditions analyzed by the author, the maximum difference of the residual velocities of the circular and non-circular cross section warheads after penetrating the target is only 4.6%; The attitude change of the projectile in the process of penetrating the target is caused by the moment acting on the projectile. Because the center of mass of the non-circular section projectile deviates from the projectile axis, while the center of mass of the circular section projectile is on the projectile axis, the attitude changes of the two kinds of projectiles in the process of penetrating the target are different. The simulation can provide a reference for the engineering design of non-circular section warhead.