Massive waste cathode carbon block are produced from the electrolytic aluminum process each year, which is mainly composed of carbon, sodium fluoride and other compounds. The fluoride and cyanide components in it cause serious environment pollution if it accumulated and exposed to air for a long time. It is regarded as a hazardous waste by various environmental bodies. An innovative method for resource processing of this waste cathode carbon block was proposed in this work. Using this waste cathode carbon block as the reducing agent can realize the effective dilution and recovery of copper from the smelting slag of Isa copper through a reduction process. According to thermodynamic analysis, the influence of the amount of waste cathode carbon addition, reduction temperature, holding time and CaO addition on the recovery ratio of copper dilution in Isa copper smelting slag was studied. The results showed that the recovery ratio of copper dilution can reach 98.24% under the conditions of waste cathode carbon addition amount of 2.0%, reduction temperature of 1300℃ and holding time of 60 min. At the same time, the F in the waste cathode carbon can be transferred and fixed in the diluted tailings in the form of CaF2. The toxic leaching concentrations of F? and CN? in the tailings were far lower than the national permissible emission standard. The research has realized the high-efficiency recovery of copper from Isa copper smelting slag and the resource utilization of waste cathode carbon.