Abstract: The penetration ballistics of a high-speed-rotating bullet on the moving sheet-metal plate is numerically studied by using of LS-DYNA. Because of the high-speed motion of the sheet-metal plate, the bullet direction will turn aside, and its trajectory becomes deflective. A method is provided to calculate the bullet turning angle. In the simulation, the bullet moving speed is 300 m/s, rotating speed is 0, 3 600 and 6 370 r/s. The sheet-metal plate moving speed is 0, 40 and 80 m/s. The head of bullet is a hemispheroid with the diameter of 7.62 mm, the sheet-metal plate is a steel sheet with the diameter of 80 mm and the thickness of 2 mm. The Johnson-Cook material model is introduced to characterize the material effects in strain hardening, strain rate hardening and thermal softening. The bullets final velocity, its turning angle and the ballistic trajectorys offset on various bullets rotating speeds and the moving speeds of steel sheets are analyzed by the simulated results.