The WC/Co coating was deposited on the surface of 37Mn5 steel by selective laser melting（SLM）. The wear resistance of WC/Co coating was tested by potentiostatic method, and the electrochemical corrosion performance was tested by seawater as medium. Results show that WC/Co coating produces diffraction peaks corresponding to (111), (200) and (311) crystal faces. The thickness of WC/Co coating is about 3 μm, which forms a rough surface structure, and scratches occur under the action of load. When the load is 5 N, the polarization curve shifts to the lower right corner, the corrosion potential also increases significantly, the corrosion current density is smaller, and the current density in the anode region significantly fluctuates. After increasing the anode potential, the passivation film has been broken down and produced microholes, resulting in a significant increase in current. When the potential of WC/Co coating increases, the friction coefficient increases, which leads to the corrosion of the coating and the increasement of wear amount. When the potential is 0.5 V, the coating has been worn through, forming a large number of pitting pit structures, scratching furrows, and a few peeling occurred at the boundary of the wear mark.