In order to improve the dynamic performance of the torsion guidance and the stability of the chainless feeding system, the rigid large-angle torsion guidance of a ramming system was analyzed and improved. By analyzing the structure and existing problems of torsional guidance, the fixed axis of torsional guidance and the change law of torsional angle with the axis were improved, and the three-dimensional model of torsional guidance was established. The virtual prototype model of torsional guidance was established by multi-body dynamics simulation software, and its motion law was simulated and analyzed at 300 radio frequencies per minute. The simulation results show that the motion of the projectile is more stable and smooth in the improved torsional guidance, which verifies the accuracy of the model.