Abstract: The welding line surface of AISI304 stainless steel was processed by shot-peening treatment,the microstructures of the material surface were observed with optical microscope and scanning electron microscope.The residual stresses of the sample by peening treatment were measured with X-ray stress tester, and the stress corrosion experiment in NaCl aqueous solution was processed.The results show that welding line of AISI304 stainless steel has obvious crack sensitivity of stress corrosion in NaCl aqueous solution;the crack is behaved with brittle rupture,which is transgranular crack;the refined hardened-layer is acquired on the welding line surface of AISI304 stainless steel by shot-peening treatment,and the compressive residual stress has greatly increased,which effectively decreases the stainless steel crack in stress corrosion.