Objective To study the corrosion behavior of Q235 steel in the S2--containing sodium aluminate solution. Methods The production conditions were simulated to prepare the mother liquor. Salt spray corrosion method together with SEM and EDS analysis technology, combined with the corrosion weight loss dynamics equation and polarization curve were used to study the effects of the Na2 S concentration and time on the corrosion behavior of Q235 steel. Results The elements of corrosion products were mainly O, S, Al and Fe. In sodium aluminate solution, the surface of the substrate was covered with a layer of Al2 O3 protective film, which could hinder the penetration of sulfur ions in the solution to the substrate surface, and play a role in the protection of the matrix. Therefore, in the early corrosion stage and at low concentrations, the corrosion rate was low, but with the increase of the concentration and the prolonged corrosion time, the protective membrane was damaged, S2- passed through the protective film and reacted with the substrate, generating sulphide which accelerated the corrosion rate. When the S2- mass concentration increased to 6 g / L and the corrosion time was 9 d, sulfide was oxidized to oxide with a relatively stable structure, the corrosion was inhibited. Conclusion In sodium aluminate solution, S2- concentration and corrosion time had a certain promoting effect of corrosion , but when the corrosion time and S2- concentration reached a certain value, the corrosion rate showed a decreasing trend, the corrosion was inhibited.