Aluminum alloy is widely used in automobile manufacturing as an important lightweight material because of its low density, high corrosion resistance and high specific strength. Cracking, wrinkling and springback are the three main quality defects in sheet metal stamping. The total elongation of aluminum alloy is smaller than that of steel plate. At room temperature, the formability of aluminum alloy is worse than that of steel plate, and it is more prone to fracture. Accurately simulating the fracture phenomenon in the sheet metal forming process is of great significance to the forming process and die design. The fracture of metal materials can be divided into brittle fracture and ductile fracture, and most aluminum alloys belong to ductile fracture. From the perspective of meso damage mechanics, the ductile fracture criterion considers that the defects of holes in the material continuously nucleate, grow and aggregate under the action of external force, and finally cause the damage of the material, which can better predict the formability of sheet metal with poor plasticity.1、 There are many factors affecting ductile fracture, which can be divided into two categories.