In order to investigate shell strength and charge in semi-armor-piercing warhead during penetration，the LS-DYNA dynamic analysis software was used to simulate the process of semi-armor-piercing warhead penetration under different landing angles on various target thickness． The curve about the stress of shell and the pressure of charge was obtained． The result indicates that the projectile structure’s integrity and safety of charges are threatened with increased target thickness; the target thickness of critical premature explosion is 25mm．