In order to avoid thermal cracks and porosity defects in the welding process of Incoloy 825 Ω ring,which is used for sealing design structure of heat exchanger,which will affect the sealing performance of heat exchanger,the horizontal fixed welding procedure qualification test of tube butt joint of Incoloy 825 was carried out by using tungsten argon arc welding. The rationality of the welding process is verified by macro inspection,non-destructive testing,mechanical test,bending test and intergranular corrosion test. The optimal welding process parameters are selected to guide the actual production operation,so as to ensure that the product quality meets the design and application requirements.