The copper grade of a carbonaceous sulfur-oxygen mixed copper ore in the Democratic Republic of the Congo is 1.27 %,and the ore oxidation rate is 25.98 %.During the beneficiation process,issues such as high  reagent  consumption,easy sludging,and low separation indicators exist.In order to achieve efficient utilization of this mixed copper ore resource,flotation test studies were conducted.The research results indicated that using a mixed flotation process with twice roughing-twice scavenging-three times cleaning stages under the conditions of 460 g/t sodium hydrosulfide,190 g/t butyl xanthate,120 g/t Z200,and 180 g/t No.2 oil,could obtain a copper concentrate with a copper grade of 17.10 % and a copper recovery of 80.76 %.