Abstract: In the process of copper flash smelting, when the content of Fe₃O₄ in slag is too high, it will result in higher copper content in slag and "material heap" phenomenon caused by precipitation pool precipitation of Fe₃O₄, which seriously affects the normal operation of flash smelting. In view of this problem, this paper analyzes and discusses the causes of the formation of ferroferric oxide in the flash smelting process, and effectively reduces the amount of ferroferric oxide in the raw materials, the optimization of the concentrate nozzle, and the corresponding control measures such as washing the furnace. The ground protection against the damage caused by ferroferric oxide in the flash copper smelting process ensures the normal operation of flash copper smelting operation