The intergranular corrosion rate index of the Incoloy825 nickel base alloy equipment can not meet the design requirement by using conventional welding technology in domestic nuclear chemical industry. Aiming at this problem,the solutions are proposed to improve and optimize the welding technology and welding material,such as using argon tungsten arc welding to weld the last run,water cooling method for the back of weld and welding material E/S Ni8025 instead of E（R）NiCrMo-3. Finally,the test results meet the qualified index of design requirements. This can provide reference for the welding technology of Incoloy825 nickel-base alloy.