Austenitic stainless steel welding method and welding assembly

The invention discloses an austenitic stainless steel welding method and a welding assembly. The welding method comprises the following steps that two welding units are assembled, wherein each welding unit is provided with an I-shaped groove and a U-shaped groove; the I-shaped groove is welded through laser deep penetration welding; and the U-shaped groove is welded by laser filler wire welding. Compared with a submerged arc welding or gas shielded welding method for large-thickness austenitic stainless steel, the method has the advantages that the depth of fusion for welding the austenitic stainless steel is more than 50mm through combination of laser deep penetration welding and laser filler wire welding. The size of a welding seam can be greatly reduced through laser welding, meanwhile, the heat input of laser welding is far smaller than that of submerged-arc welding or gas shielded welding, welding deformation can be effectively controlled, and the laser welding seam is high in quality and few in defect.