Aiming at the launch strength problems caused by random factors in the process of interior ballistic, taking a certain type of APDS interior ballistic environment as an example, the influence of the change of the chamber pressure time series curve caused by the change of propellant combustion environment on the projectile launching strength was simulated by ABAQUS software. The simulation result shows that under the same maximum chamber pressure, the faster the change rate in the ascending stage or the slower the change rate in the descending stage, the greater the sabot stress and the lower the emission intensity. This conclusion can provide theoretical reference for the relevant engineering design, and it is of great significance to the strength analysis of the projectile in the process of internal ballistic.