TiNi shape memory alloy has good biocompatibility and superelasticity on the basis of certain strength and stiffness. In the process of tooth correction, stainless steel of composite orthodontic arch wire is used as the support of supporting teeth. TiNi alloy of composite orthodontic arch wire is used to correct the dislocation teeth. Compared with the traditional stainless steel arch wire, composite orthodontic arch wire can reduce the pain of patients. In this experiment, laser welding was carried out by filling Cu filler metal. Laser centering welding and laser offsetting welding were used respectively, and the joint strength was compared. It was found that laser offsetting welding can effectively reduce the content of interface intermetallic compounds and improve the joint strength.