equal channel angular extrusion/Pressing (ECAE, ECAP) has the capability of producing ultra-fined grain (UFG) materials bellow the dimension of 1 μm. At present, it is one of the most important methods to get bulk UFG materials. In this paper, a systematic investigation of ECAP process on the pure Aluminum and die design is performed by using numerical simulation. The stress distributions on the die were obtained, and general consideration of the die during the whole pressing process was given. it was found that the closer the die corner is, the higher stress value results can be acquired. And the effective stress concentration in ECAP die cavity corner. The extruding load fell rapidly when the angular angle increasing. The proposed method can serve as preconditions to analyze the abrasion and fatigue of ECA Pressing die.