Abstract: The large consumption of thiosulfate in the process of leaching gold and silver by ammonia thiosulfate is one of important factors that hinders the application of this technology in industry. In the leaching system, the concentration of copper ions and copper ammine complex ions are the key factors that affect the consumption of thiosulfate. The purpose of reducing thiosulfate consumption can be achieved by regulating the concentration of copper ions and copper ammine ions, adding additives, and pre-treating ore.