The process of irregular flat tube which used in the car chassis was analyzed, and the cold forming process that two symmetric parts were produced at one time was formulated. In the process, the tube bending forming following the tube flattening, drilling, cutting and burring processes were adopted. In the designed process scheme, the irregular flat tube structure features were adequately considered, and the compact process of the combination of bending and flattening was adopted. At the same time, some related dies and checking tools were designed, which guaranteed the product quality. The production practice proves that the designed process scheme can have a high working efficiency, save raw materials and have good product quality, which could bring benefits for the enterprise.