Dynamic engraving process of 23 mm projectile was studied using numerical simulation. A finite element model of projectile and barrel during the engraving process was constructed, and the deformation process of the driving band, the displacement parameters of the projectile, the force interaction between the projectile and the barrel were determined. To evaluate the simulation model, a semi-static experiment was carried out on an MTS-810 universal testing machine with a cross-head speed of 20 mm min−1. The simulation results show that the mechanism of the 23 mm projectile rotating band engraving process is the plastic deformation process of the rotating band material, engraving time is 1.12 m s, and the projectile velocity after engraving is 105 m s−1. The simulation results reflect the actual rotating band engraving process, which is very distinct from the assumptions used in the classical ballistic model. This work provides an approach to investigating the interior ballistic processes considering the dynamic engraving of rotating bands.