Abstract: TIG sealing welding experiments of tube plate made of Gr.1+S30403IV（12 mm+328 mm） and Gr.2 heat transfer tube（φ19.05 mm×2.41 mm） were performed. Visual test（VT）, penetration test（PT）, low power metallographic examination and microhardness test of the welded joints were conducted. Mock-up test method for the welded joint was designed and strength of the welded joints was tested. It has been verified that the weld groove form has significant influence on the weld appearance and full penetration in the root. The welded joints that can meet the requirements of VT, PT and low power metallographic examination were obtained by using the optimized groove and welding parameters. The mock-up test results show that the tensile strength of the welded joints is higher than the requirement value of the tube. The optimized welding technology was applied to the welding of tube to plate in actual product, the welded joints could meet the requirements of PT, helium leakage detection and hydraulic test.