Abstract: By using the analytical method of conical projectile, a modified petalling perforation model of the ogive-nose projectile oblique penetrating thin metallic plate was established according to the energy conservation principle. The formulas for the energy of the propagation of radial cracks, petal dynamic power and petal bending were deduced on the basis of the ogive-nose projectile's characteristic. The application range of the model was discussed as well. The model provided in this paper could give satisfied predictions of the projectiles' residual velocity of the projectile for both vertical and oblique penetration which is precise than the results of empirical formula if the deformation of the projectile can be neglected.