Copper anode sludge was a byproduct produced during the refinery of copper. The sludge contained amount of noble metals and rare metals, and also was an important resources for recovering noble metals. In this paper, ammonium thiocyante was used as leaching reagent for extracting gold from arsenic-free anode sludge (secondary sludge). Under the optical conditions, the leaching efficiency was up to 85.1%, while the dynamic behavior of gold leaching was studied, the activation energy of the system Eα=20.093kJ•mol-1, and reaction velocity constant k=4.084e-20093/RT. The treatment of copper sludge could greatly reduce the potential contamination to the environment.