Objective The characteristics of Ni-P alloy coating after electrochemical etching were investigated.Methods Ni-P alloy coating was etched by the electrochemical etching method. The surface, microstructure, phase composition, elementary composition and etching depth were characterized. The hardness of etching coating was tested by the microhardness tester. The binding strength between etching coating and substrate was tested by thermal shock technology. The penetration of etching micropores was characterized by using polarization curves. Results The results showed that: the surface of Ni-P alloy after electrochemical etching would turn tarnish and dark. The electrochemical etching micropores first appeared on borders of the cellular materials,then spread to the surface of cellular materials.The etching micropores were in right size and distributed evenly under optimal conditions of electrochemical etching.The etching micropore didn爷 t penetrate the Ni-P alloy layer to the substrate. Conclusion The electrochemical etching had little effect on the binding strength, but reduced the hardness of the etching layer.