The copper grade of a sulfide-oxide mixed copper ore from Sichuan is 1.95 %, with sulfide copper and oxide copper accounting for 71.54 % and 28.46 % of the total copper minerals, respectively. To address the problem that sulfide copper minerals have good flotation properties while oxide copper minerals have poor flotation properties, a joint flotation-leaching metallurgical process was studied. Through flotation condition experiments, the optimal process parameters were determined: a grinding fineness of 75 % passing -0.074 mm, 1 000 g/t of Na2CO3 as pH adjuster, 1 360 g/t of HD2 as activator, 750 g/t of butyl xanthate as collector, and 50 g/t of No. 2 oil as frother. Under the optimal conditions, the flotation closed‐circuit test yields a flotation concentrate with a copper grade of 25.25 % and a copper recovery rate of 65.08 %. Through sulfuric acid leaching tests on the flotation tailings, under the conditions of a liquidto‐ solid ratio of 11∶5, sulfuric acid dosage of 150 kg/t, and leaching time of 60 min, the copper leaching rate from the flotation tailings reaches 78.22 %, and the overall copper recovery rate reaches 92.39 %. The research results provide technical support for the efficient development of sulfide-oxide mixed copper ore resources.