In order to solve the problems of low efficiency, low material utilization, high production cost and poor product performance in the traditional manufacturing process of an automotive flange part, a three-station hot die forging process was designed, which consists of preforming, pre-forging and final forging in sequence. Then, to ensure the process quality, the forming process of flange part was simulated by software Deform-3D, and the hidden defects in the process were determined based on the metal deformation process. Furthermore, the pre-forging die structure was optimized, and two improvement schemes were proposed. At the same time, the forming inspection was carried out in turn, and the temperature distribution of final forgings, the forging force of pre-forging and final forging stations, and the die wear conditions of the two improved schemes were compared. The results show that the improved process solves the forging defects, and the improvement scheme 2 is more helpful to improve the quality of flange forgings and prolonging the life of die. Finally, hot die forging tests of flange parts are carried out, and the expected flange parts are obtained, which effectively solves the current problems.