Abstract:  In order to study the influences of bending process on the forming quality and microstructure of a certain aluminum alloy control arm, the forging process of the aluminum alloy control arm was numerically simulated by software Deform-3D, and the design of bending mold cavity was optimized. The results show that under the same process parameters, the change of bending angle and shape for the bending mold cavity affects the flow and deformation amount of the metal, and the unreasonable design can cause abnormal recrystallization, thus affecting the width of outline coarse grains. After the optimization on the bending angle and shape of the bending mold cavity, the deformation of billet during the pre-forging is more uniform, the temperature rise caused by deformation and friction is effectively reduced, and the thickness of outline coarse grain is controlled. Thus, the thickness of outline coarse grain at section A-A of the aluminum alloy control arm is reduced from 6 mm to only 2 mm.