In order to solve the cracking problem of seat belt early warning device bracket for 6016-T4 aluminum alloy, first of all, the structural characteristics, stamping process and material performance of seat belt early warning device bracket were analyzed, and based on the finite element software Dynaform, the whole process of early warning bracket was simulated to determine the cracking position and analyze the cause of part cracking. Then, the die fillet radius of OP30 flanging process was increased from the initial 5.5 to 8.0 mm to solve the cracking problem of bracket. Through the orthogonal test of four factors and three levels, the importance degree relationships for the influence of stamping speed, blank holder force, friction coefficient and clearance between die and punch on the maximum thinning rate of evaluation index in OP30 flanging process were studied, and the optimum combination of process parameters was obtained. Finally, the simulation verification result shows that the thickness of bracket is effectively controlled within 1.679-3.018 mm by increasing the fillet radius combined with the optimized process parameter combination, which greatly reduces the thinning rate of sheet metal, and there is no cracking phenomenon in the bracket, which is convenient for subsequent stable mass production.