The work aims to deposit FeCoCrNiCu high-entropy alloy coating on 45Mn2 steel to improve the surface proper-ties. FeCoCrNiCu high-entropy alloy rod with a dimeter of 3 mm was prepared by copper mold suction casting and the FeCoCrNiCu high-entropy alloy coating was deposited on 45Mn2 steel surface by electro-spark deposition technique. The phase composition, surface morphologies and microstructures of the deposited coatings were analyzed by optical microscope (OM), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The electrochemical corrosion behaviors of the deposited coating in 3.5%NaCl were measured by polarization curves and electrochemical impedance spectroscopy. The prepared FeCoCrNiCu coating was continuous and uniform with a simple FCC structure. The surface was silver-gray orange peel and about 25 μm thick. The surface of the coating was uneven and showed typical "sputtering" pattern. The root mean square deviation (Rq) of the surface roughness was about 4 μm. The polarization curves showed that the self-corrosion potential of the high-entropy deposits was -0.548 V, which was 180 mV higher than that of 45Mn2 substrates, and the corrosion current density was 1.59 μA/cm2, which was about 1/6 of that of the substrates. The EIS results of electrochemical impedance spectroscopy showed that the FeCoCrNiCu high-entropy alloy deposit had larger capacitive arc radius and polarization resistance than 45Mn2 substrate, and the analog circuit could be expressed by R(Q(R(QR)). Electro-spark deposition (ESD) is a promising technology for preparing high-entropy alloy coatings. The high-entropy FeCoCrNiCu coating prepared can effectively improve the corrosion resistance of the substrate.