Forged plates of high-manganese austenitic heat-resistant steels with and without addition of V and W were made, and then subjected to solution treating at 1050 ℃ for 1.5 h and quenching in water. Their hot-corrosion behavior was comparatively assessed in molten Na₂SO₄ at 900 ℃ in air. The microstructure of the steels, as well as the morphology, phase constituents and composition of corrosion products were characterized by means of scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), energy dispersive spectrometer (EDS) and X-ray diffraction (XRD). The results showed that the high-manganese austenitic heat-resistant steel containing V and W exhibited resistance to molten Na₂SO₄ superior to the steel without addition V and W. The corrosion kinetics curves of the two steels presented a double parabolic relationship, indicating that with the extension of corrosion time, the two steels suffered from accelerated corrosion. However, the high-manganese austenitic heat-resistant steel containing V and W had a longer incubation period for accelerated corrosion compared to the ones without V and W. The accelerated corrosion behavior of the steel without V and W was mainly influenced by internal oxidation and internal sulfidation. The (Cr, V)₂O₃ inner oxide scale formed on the high-manganese austenitic heat-resistant steel containing V and W could protect the matrix in the early stage of corrosion, enhancing the hot corrosion resistance to molten salts for the steel. However, when (Cr, V)₂O₃ transformed into (Cr, Fe)VO₄, it could react with the molten salt, thus facilitated the inward infiltration of molten salt to form metavanadate/vanadate, causing the accelerated corrosion of the high-manganese austenitic heat-resistant steel containing V and W.