Abstract: To determine the optimum ratio of arsenic-contaminated soil with different concentrations, SP-MOC curing of arsenic-contaminated soil and toxicity leaching test are carried out in the relocation of a chemical plant in Jiangsu Province. The change law of moisture content, pH value and leaching concentration of solidified body under different curing agent ratios are investigated, and the effect of curing age on leaching concentration is analyzed. The results show that the moisture content of the solidified body is negatively correlated with the curing age, and the pH value of the solidified body increases with the increase of the curing agent content, reaching the maximum pH value when the curing age is 14 days. With the increase of arsenic pollution concentration, the ratio of needed curing agent increases. When the background value of arsenic is 90 mg/kg, 188 mg/kg, 275 mg/kg, and 339 mg/kg, the curing agent ratios satisfying the leaching limit are 3%, 5%, 8%, and 8%, respectively. The leaching concentration decreases first and then increases slightly with the increase of curing agent content. When the content of curing agent is 8%, the leaching concentration reaches the minimum. The leaching concentration decreases with the increase of curing age, and reaches the minimum after 14 days of curing.