With an automobile aluminum alloy connecting rod, based on traditional forging, the blank calculation method of cross wedge rolling was put forward. As to one section, its position should first determined in shank part or head part, then the calculation method of diameter and length of this section was given. Next, the optimization evaluation of blank shape was discussed. Finally, the finite element simulation process of aluminum alloy connecting rod was carried out. The results show that using cross wedge rolling to make the aluminum alloy connecting rod not only could make technology simple, but also the fin only occupied 16% volume of the connecting rod, the reasonable shape of blank could make the deformation uniform objective value, deformgation force and damage value reach the minimum. All these confirm that it is right to use cross wedge rolling for optimizing blank.