Abstract: By controlling the Ni and Cr equivalents, six types of matching welding materials for SiN austenitic stainless steel were designed and prepared. The hot cracking resistance of the fillers was evaluated using a circular block welding test, and the optimal filler composition was determined. Furthermore, the mechanical properties and nitric acid corrosion resistance of the welded joints were tested. The results indicate that no welding hot cracks occur when the δ-ferrite content in the weld metal reaches 8.2%. Compared with 304L stainless steel, the welded joints of SiN stainless steel exhibit higher tensile strength. In a simulated spent fuel reprocessing solution (6M nitric acid containing a certain concentration of oxidizing cations) at 95℃, the corrosion rate of the SiN stainless steel welded joint is approximately 0.1 mm/a, only one-fourth of the corrosion rate of the 304L stainless steel welded joint.