Abstract: Aiming at the cyanide-containing wastewater produced by the cyanidation of gold concentrate in a gold production enterprise, focusing on the treatment problems caused by the coexistence of high-concentration cyanide and copper ions, the technical path of copper recovery by sulfide precipitation method was proposed and systematically studied. The effects of precipitant type (sodium sulfide and sodium hydrosulfide), dosage, reaction pH and reaction time on copper recovery rate were systematically investigated by comparative single factor test. The experimental results show that both precipitants can achieve efficient recovery of copper under optimized conditions. When sodium sulfide was used as precipitant, the recovery rate of copper was 98.3 % under the optimum conditions of dosage 4 g/L, reaction pH value 5.0~5.5 and reaction time 15 min. When sodium hydrosulfide was used as precipitant, the optimum conditions were as follows: dosage 1.25 g/L, reaction pH value 5.0~6.0, reaction time 15 min, and the corresponding copper recovery rate was 98.5 %. Comprehensive comparative analysis found that under the premise of similar high recovery rate, sodium hydrosulfide showed a wider effective pH adaptation range and lower unit reagent consumption cost. The reason was that sodium hydrosulfide precipitated copper to form H⁺, the pH buffer capacity was stronger, and the sulfur content in unit mass sodium hydrosulfide was higher. Therefore, sodium hydrosulfide is recommended as the preferred precipitant for copper recovery in this wastewater system. After this process, the copper grade in the obtained copper-containing material reaches 58.3 %, and the impurity arsenic content is 0.0077 %, which meets the product standard of T/GGA 008-2017 Cyanide Copper Mud. This study not only alleviates the potential harm of heavy metal accumulation to subsequent production systems by removing copper ions, but also converts pollutants into valuable resources, which provides a feasible technical solution for enterprises to achieve the synergy of environmental and economic benefits, and helps to promote the clean production and sustainable development of the gold smelting industry.