When untreated calcium arsenate slag is exposed to the natural environment,it can reacts with carbon dioxide and releases arsenate ions with different valence into the soil or river,and causes environmental pollution.In this study,cement solidification was used to solidify the calcium arsenate slag which provided by an enterprise in Yunnan.The cement solidification effect of calcium arsenate slag with different mass ratio was studied.By the compression test and toxicity leaching test,it is found that the toxicity leaching value of the solidified body is not more than 1 mg/L,which is lower than the national standard requirment of 1.2 mg/L.The compressive strength of the solidified body is more than 10 MPa,which meets the national requirements for safe landfill or accumulation of arsenic containing waste residue.