To reduce the ratio of weight to volume and realize the lightweight, the welding technology under the “Double carbon”target has put forward higher application requirements.In this paper, the application of high efficiency deep penetration Argon arc welding technology in strain-strengthened vessel is studied, the changes of strength, fracture morphology, plasticity, toughness, microstructure, grain size and slag inclusion of the welded joint of domestic austenitic stainless steel S30408 welded by K-TIG process under 0% pre-stretched, welding seam specimen made from the product welding test plate after pre-stretched by stress control method and the specimen made from the strain-strengthened vessels were analyzed and compared. The results show that welding joint quality is stable, the weld appearance is beautiful, and the production efficiency is greatly improved. The properties of the samples under different conditions of A,B and C all meet the standard requirements. After strain strengthening, the yield strength increases significantly, which stimulates the plasticity reserve, effectively improves the ratio of yield to strength, and brings into full play the bearing capacity of the material to a greater extent, thus increasing the practical allowable stress of the material, it can be used in the manufacture of low temperature pressure vessel.