Abstract: A high sulfur copper mine is rich in valuable resources such as copper, iron and sulfur. The sulfur content in the tailings after copper pre-flotation is quite high. In order to recover and utilize sulfur resources and reduce the sulfur content of the tailings to reduce its harm to the environment, the experiment of sulfur activation and flotation from the copper tailing is carried out. Through the study of process mineralogy, the distribution characteristics of various kinds of minerals, and the main sulfur carrier mineral pyrite in the pre-processed copper tailings are clarified. According to the distribution characteristics of the tailings, the control variables tests are carried out based on a roughing flowsheet, and the influence of the type and dosage of activator and collector on sulfur separation is investigated. It’s found that the optimal dosage of sulfuric acid as activator is 3 000 g/t, and the optimal dosage of xanthate as collector is 150 g/t. The effect of dosing method on flotation is investigated, and it is proved that xanthate acted better when it is dosed segmentally in the roughing and sweeping stages, which could effectively reduce the sulfur grade of the flotation tailings and weaken its environmental impact. A sulfur concentrate with 49.6% sulfur grade and 98.45% recovery rate can be obtained under the best reagent scheme and the flowsheet of one rough and two sweeping. The sulfur grade of the tailings can be reduced to 3.55% accordingly. For further optimization of the flotation process and parameters, process mineralogy analyses are conducted on the sulfur flotation concentrate and the medium mineral products, and their mineral composition, symbiosis relationship and element content are investigated. It’s found that pyrite is not completely dissociated, and its industrial utilization value is low. It’s difficult to be separated if without regrinding. This study can provide a theoretical reference for the high efficiency recovery of other sulfur tailings with similar types.