Friction welding process, with outstanding welding strength optimization design, adopts seamless tube integral welding to effectively improve the connection strength of the frame longitudinal beam. The fatigue test of the torsion bench can reach up to 80000 times. After forging, friction welding process welding is used to avoid casting structure crystallization defects such as porosity segregation and inclusion cracks in the weld seam, and enhance the toughness and strength of the product. Seamless cold drawn tubes and high-strength automotive structural steel are used for automatic welding, with high strength and light weight, and wide application.