Abstract: Strong alkalinity is the key factor restricting the comprehensive utilization of red mud and acid leaching is an effective method for the dealkalization of red mud. Most studies have focused on the recovery of metals in this extreme alkaline waste by strong acid leaching, ignoring the dealkalization and stabilization of red mud with low concentrations of acid. In this study, the leaching behavior of Na in red mud with low concentration of sulfuric acid was carefully investigated and the effects of sulfuric acid concentration, liquid-solid ratio, stirring speed, leaching temperature and leaching time on red mud dealkalization were investigated. The results show that treatment with an acidic solution at pH 1 removed 17.84% of Na. Greater than 60% Na was leached by an acidic solution with H⁺ concentration of 0.5 mol/L, resulting in a relatively simple leaching liquid treatment process. And the pH of the leaching residue was 8.5 which slightly alkaline so the residual RM could be used as soil aggregates. Under the optimal conditions of H⁺ concentration 1.6 mol/L, solid-liquid ratio 1/4 g/mL, stirring speed 300 r/min, leaching temperature 298K and leaching time 10 min, the dissolution efficiency of Na reached at 94.70%, leaving only 0.6% Na in the residue, which makes it possible to meet the demand of application for construction materials. We also investigated the sulfuric acid leaching kinetics. The results show that the sodium leaching process is mainly controlled by the product layer diffusion model and the apparent activation energy of the leaching process is 16.99 kJ/mol in low concentration sulfuric acid medium. XRD analysis shows that calcite reacts with sulfuric acid to form calcium sulfate microsoluble substance is the main reason for the formation of product layer. Based on the above results, a new multistage acid leaching process was proposed, which laid a foundation for the comprehensive utilization of red mud.