High temperature chlorination roasting was used to treat certain gold smelting slag,and the gold in the slag was volatilized into the dust in the form of chloride,then sprayed by wet dust collection equipment to collect the acid leaching solution with pH=0.16 and gold mass concentration 1.21 mg/L that is worth recovery.Gold was recovered from the acid leaching solution by sulphuration precipitation method.The effects of precipitators,reaction time and reaction temperature on gold precipitation rate were discussed.The results showed that the precipitation rate of gold reached 99.17 % with methyl mercaptan sodium as precipitant at the conditions of precipitant-leach solution volume ratio 1∶2,reaction time 40 min and reaction temperature 40 ℃,then high purity gold products can be obtained by washing and roasting.