In order to evaluate the anti shock overload ability of electronic components and parts in explosive device launcher, half sine wave generator with certain amplitude and pulse width is often used to verify it. In this paper, gun launcher is used as the shock wave generator. Different charge structures are studied for the interior ballistics process of barrel with or without venting according to certain requirements of mechanical overload. The influence of different charge structure, chamber volume and vent hole size on the overload waveform of projectile in the process of interior ballistic is studied by numerical simulation. The simulation results show that the larger the vent diameter is, the closer it is to the standard waveform. The research results can provide references for the matching design of projectile and artillery, the research and development of intelligent ammunition and the assessment. The research results can provide for the matching design of new artillery projectile and artillery and the research and development of intelligent ammunition.