<p>The advancement of industrial processes generates significant quantities of arsenic-containing wastewater, which poses a considerable risk of arsenic pollution. Consequently, the safe treatment of arsenic-laden materials has emerged as a critical challenge that impacts both the sustainability and growth of the industry. In this study, the effect of copper ions on the precipitation of scorodite in the process of hydrothermal systems of industrial arsenic-containing wastewater was investigated. In hydrothermal systems, due to the catalytic effect of Cu²⁺/Cu⁺ ion pairs, the oxidation rate of ferrous ions was significantly accelerated. As the concentration of copper ions increased to 20&#xa0;g/L, the iron precipitation rate increased from 63 pct to more than 75 pct, and the amount of scorodite precipitation increased significantly. In addition, the role of copper ions in the formation of scorodite was further verified by simulation calculations. The results were consistent with the experiments. Copper ions (Cu²⁺) enhanced the coprecipitation of arsenic and iron, resulting in the formation of well-crystallized octahedral scorodite particles. The research results are of great significance to the hydrothermal precipitation process of scorodite in industrial arsenic-containing wastewater.</p>