Diamond-nickel-based composite coatings with directly added Cu and Cu-coated diamond were prepared by induction heating technology. The effects of Cu addition on the microstructure, physical phase evolution, microhardness and wear properties of diamond-nickel composite coatings were investigated. The results show that the direct addition of Cu and the introduction of Cu in the form of Cu-coated diamond in the diamond-nickel-based composite coatings inhibit the generation of carbides in the nickel alloy matrix, and when added in the form of Cu-coated diamond, almost no carbides are observed in the nickel alloy matrix; the average microhardness of the coatings coated with Cu-coated diamond decreases by 76.7 HV compared to that of the direct addition of Cu. Moreover, the coatings showed more excellent wear resistance in the 15min~45min wear stage of the abrasive wear test.