The use of the LS-DYNA procedure to simulate the projectile of different head shape contacting thin target at different impact angle and obtain the maximum set-forward overload factor provide reference for designation of inertia contact device of fuze. The results show that the maximum set-forward overload factor appears while the projectile contact target is in a small impact angle which changes along with the materials and thickness of the target plate rather than contacting positively, so the impact angle generated by the error of the target plate and attack angle's influence on the contact sensitivity and insensitivity tests must also be considered. Designing different projectile shape, there is great differences in the maximum set-forward overload factor, so while designing projectile shape, the aerodynamic characteristics and the set-forward enviroment must be considered.