Abstract: In order to realize the domestic manufacturing of nuclear-grade austenitic stainless steel pipes TP321 instead of 08X18H10T steel used in the original design for nuclear power station. The effects of chemical composition, manufacturing process and heat treatment on tensile properties at room temperature and 350 ℃, microstructure, grain size and anti-intergranular corrosion property of the TP321 steel were analyzed to find a suitable chemical composition and technique. The results show that the modified process which used blank with big dimension, and added a path of cold-rolling, one middle heat treatment and one cold-drawn process based on the original process, and then solution treatment at 1 100 ℃ for 11 min was set up. The tensile strength at room temperature of TP321 steel prepared by the modified process increased from the original process of 540 MPa to 556 MPa; the yield strength increased from 170 MPa to 250 MPa; the grain size was 4.5. By controlling the chemical composition, the domestic TP321 steel can both meet the requirements of ASME and reached the mechanical properties of 08X18H10T steel, and finally realized the domestic manufacturing of nuclear-grade austenitic stainless steel pipes.