Abstract: Objective Hastelloy C2000 alloy is widely used in the corrosive environment of nuclear industry, and has high requirements for weld quality. The aim is to research Hastelloy C2000 welding process. Methods The welding test of Hastelloy C2000 alloy with a thickness of 8 mm is carried out by TIG welding method, and the filling material is ERNiCrMo-17 welding wire with a diameter of 2.0 mm, the performance and structure of the joints are tested and analyzed. Results The results show that, under the welding process parameters provided in this paper, the Hastelloy C2000 alloy welds are well formed, there are no obvious defects such as porosity and cracks in the joints, and radiographic inspection results meet quality requirements of the standard. Welding zone microstructure of capping pass and filling pass is dominated by columnar grains. The microstructure in the root pass zone is mostly equiaxed grains, with a large number of precipitated phases near the grain boundaries. Under the tensile test, the fracture of specimen occurres at base material, and no crack is found in the 180° bending test of joints, and the distribution of joint hardness tends from big to small is weld zone, heat-affected zone, base material, the hardness of welds zone is 237.4～245.6 HV, and the intergranular corrosion rate of welds is 2.13 g/(m²·h). Conclusion Under the process parameters of this paper, the weld has no defects, the joint performance is good, and the weld quality meets the requirements of use in corrosive environment, which provides a certain reference for the application of Hastelloy C2000 alloy in engineering.