The work aims to improve the hardness, friction and wear resistance and corrosion resistance of Cu-Ni composite coating. Cu-Ni and Cu-Ni/CNT composite coatings were prepared through electro-codeposition by adding nickel sulfate hexahydrate and carbon nanotube (CNT) in copper sulfate pentahydrate plating solution. The hardness and friction and wear properties of composite coating reinforced by CNT (Cu-Ni/CNT) were investigated by micro-hardness meter and tribometer; and the surface morphology, element distribution and morphology of wear scar of the coating were characterized by scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The electrochemical impedance spectroscopy (Nyquist) and Tafel curves of the coatings were measured in 3.5%NaCl solution. When Cu and Ni were co-deposited, more Ni atoms were replaced by Cu atoms, which caused the hardness of the coating slightly lower than that of pure nickel coating, but the wear resistance of the coating was enhanced due to solid solution after the formation of Cu-Ni solid solution. CNT co-deposition in Cu-Ni composite coating resulted in grain refinement and dispersion strengthening effect, which increased the coating hardness to 560.59HV in the range of investigation. When the Cu-Ni co-deposition plating solution was added with CNT with the mass percentage of 0.08%, the composite coating presented the highest corrosion potential of -436.08 mV due to the physical shielding of CNT, and the lowest self-corrosion rate and corrosion resistance. The coating resistance Rc was (1573 Ω?cm2). Compared with the pure Ni coating, the corrosion suppression efficiency of Cu-Ni/CNT (0.08%) was 95.86%, the average friction coefficient of the coating was 0.52 which was the lowest, and the wear resistance was also the best. In the co-deposition process of Cu-Ni/CNT, the addition of CNT with appropriate mass percentage can effectively enhance the hardness, friction and wear properties and corrosion resistance of Cu-Ni composite coating.