The deposition temperature of cold spray is relatively lower than that of thermal spray, thus the coatings prepared by cold spray technology can effectively avoid coating oxidation and thermal stress damage of substrate. Cold spray technology is a kind of solid deposition technology of materials which has developed rapidly in recent years. The work aims to prepare Cu/AlN coatings with high density and high hardness on Cu substrate by adding AlN ceramic particles and study the effects of different feedstock powder pretreatment processes on the microstructure and properties of cold sprayed Cu/AlN composite coatings. 100 mm×100 mm×3 mm Cu substrate was taken as the base material. Cu powder and AlN powder were used as raw materials. Cu-AlN mixed powder and Cu-Cu@AlN mixed powder were prepared by ball milling process and electroless plating process as spraying materials, respectively. During the cold spray process, N2 (3.5 MPa, 600 ℃) was used as the carrier gas, and the distance between the spray gun nozzle and the substrate was 30 mm. The microstructure and porosity of the coating section was analyzed by scanning electron microscope (SEM). The composition of coating elements was characterized by energy dispersive spectrometry (EDS), and the amount of AlN deposited in coating was calculated. The microhardness and electrochemical corrosion properties of the coating were measured by Vickers hardness tester and electrochemical workstation. The effects of different pretreatment processes (ball milling and electroless plating) on the microstructure, mechanical properties and corrosion resistance of the coatings were studied. The SEM results showed that Cu-Cu@AlN and Cu-AlN coatings had denser microstructure, fewer pores and better bonding with substrate than pure Cu coating. The deformation of Cu particles was strong, while the deformation of AlN particles was not due to the high hardness and low ductility. The EDS results showed that AlN was uniformly distributed in the coating, and the content of AlN in Cu-Cu@AlN coating was significantly higher than that of Cu-AlN coating. The microhardness of Cu-AlN coating prepared by ball milling was 138.7HV, which was 56% higher than that of copper substrate. The self-corrosion potential of Cu-AlN coating was ?0.228 1 V, and the corrosion current density was 15.1 μA/cm2. The hardness of Cu-Cu@AlN coating prepared by electroless plating process was 151.8HV, which was 71% higher than that of copper substrate. The self-corrosion potential of the coating was ?0.166 7 V, which was 70.4 mV higher than that of the Cu-AlN coating, showing lower corrosion tendency and the corrosion current density was 1.18 μA/cm2, which was an order of magnitude lower than that of the Cu-AlN coating, showing better corrosion resistance. Electrochemical impedance spectroscopy test results showed that Cu-Cu@AlN coating had the highest charge transfer resistance (1 625 Ω.cm2), confirming that it had the best corrosion resistance, which was consistent with the results of potentiodynamic polarization technology. The electroless plating process improves the mutual wettability between Cu powder and AlN powder, thereby improving the dispersion uniformity of AlN in the coating, promoting the interface combination with Cu, making the coating denser and improving the corrosion resistance of the coating.