Chromium slag and chromium-containing wastewater produced by some industrial and mining enterprises in our country often cause serious chromium pollution in soil due to poor management. It is urgent to seek low-cost remediation technology for chromium-contaminated soil. A technology for eluting chromium-contaminated soil with an extract of Dissolved Organic Matter (DOM) in decomposing rice straw was proposed. Through laboratory simulation tests, two types of chromium contaminated soil (the total chromium content is 121.54 mg/kg and 941.90 mg/kg respectively, and the hexavalent chromium is 119.90 mg/kg and 856.90 mg/kg respectively) as the research goals. The effect of solid-liquid ratio, leaching time, leaching times and other factors on the elution effect of total chromium and hexavalent chromium in the soil was investigated by the oscillation leaching method. The chromium form changes before and after leaching and the continuous passivation ability of hexavalent chromium remaining in the soil after leaching were also discussed. The results showed that DOM extract from rice straw decomposed for 35 days had the best effect of eluting chromium in soil and was determined as the best eluent. The solid-liquid ratio is 1:15, leaching for 4 h/ time, and leaching for 2 times is the best leaching process condition. Under this condition, the total chromium content in soil is eluted by 47.79% and 85.92%, and the hexavalent chromium content is reduced by 51.76% and 95.09%, respectively. DOM extract is weakly alkaline and contains a large number of carboxyl, hydroxyl and phenolic substances. It has good elution effect on chromium in water soluble, weak acid extracted and residue state, effectively reduces the environmental risk of soil, and can continuously passivate the residual hexavalent chromium in the leached soil.