Abstract: The ballistic trajectory effect of the fragment simulation projectile was experimentally researched by A3 steel cylindrical projectiles (diameter of projectile 25 mm) impacting 45 steel plates. The intensity of A3 steel is less than that of 45 steel. In the velocity ranges of 200～800 m/s, Taylor impact, petal-cap failure of sunflower alike and plugging perforation are observed respectively in the plates with increasing velocity. Complicated material failures of projectile and target conflict with the different penetration mechanisms.