A mechanics model of multi-point die that contained complicate multi-contact surfaces was built by elastic-plastic finite element method, different materials with different thickness and deformations of spherical surface parts were simulated during the forming process, the variation histories of maximal contact forces of punches and their correlative factor were analyzed. The results indicated that the contact forces of punches became larger and larger along with the increase forming forces, when the elastic modulus and yield strength of material were bigger, the thickness and deformations of parts were also bigger. 