For the folding defects that occurred during the die forging process of  aluminum alloy air suspension support arm for a certain type of automobile, combining numerical simulation and production process optimization, the forging forming process was simulated by Forge software, and the metal flow characteristics were analyzed. Then, it was revealed that the main cause of  folding was the metal reflux and hedging caused by the small transition fillet radius of die and the improper placement of billet, and two optimization schemes were proposed, namely, optimizing the die fillet and adjusting the placement position of billet. The simulation results show that increasing the die fillet radius at the parting surface from R3 mm to R8.5 mm  and widening the bridge can transfer the folding area to the flash. Adjusting the placement position of billet to make it tilt along the curvature of die cavity can optimize the metal flow path and eliminate the metal confluence in the cavity, which can completely eliminate the folding defects. Finally,verified by the actual production,the quality of forgings is significantly improved,which provides an effective method for improving the forging process of complex aluminum alloy parts.