Aiming at the phenomenon that the feeding system of a high firing rate aircraft gun stops firing due to the shell jamming, the causes of the failure are researched. Based on the multi-rigid-body belt model with complex hinge connection, the numerical simulation model was established by programming, and the movement law of the projectile at the tail of the belt was obtained by simulation, which was basically consistent with the real experimental data. Further simulation results show that the acceleration perpendicular to the movement direction is too large in the movement process of the tail shell of the belt, and the tail shell has the phenomenon of tail swing, which increases the feeding resistance and causes the system jamming failure.