The work aims to improve the mechanical properties and corrosion resistance of H13 steel surface, so as to extend the service life of mould. Niobium deposited coating was prepared on H13 steel substrate by electrospark deposition process with niobium electrode as coating material and argon as shielding gas. Surface morphologies, microstructures and wear morphologies of the deposited coating were analyzed by scanning electron microscope (SEM). Phase composition and elements distribution of the coating were tested by X-ray diffractometer (XRD) and energy disperse spectroscopy (EDS). Microhardness and wear resistance of the coating were measured by microhardness tester and wear tester. Corrosion resistance of the coating was determined by electrochemical workstation. The surface of niobium deposited coating mainly consisted of Fe2Nb and Fe0.2Nb0.8 looked like the surface of orange and had certain roughness. The microstructure of the coating cross section was continuous and dense without obvious defects. The strengthening coating contained plenty of microcrystalline structures and amorphous structures. The diffusion of chemical elements occurred between the niobium coating and the H13 steel substrate. The microhardness of the coating was 642HV, which was about 3.2 times higher than that of the H13 steel substrate. The wear mass loss of niobium coating was about one third of the H13 substrate in the equal wear conditions and the wear scar was shallow. The electrochemical self-corrosion potential of the coating in 3.5wt.% NaCl solution was improved by about 113 mV compared with the substrate, while the electrochemical self-corrosion current density was decreased obviously. Nb coating deposited on H13 steel substrate by electrospark can effectively improve microhardness, wear resistance and corrosion resistance of the H13 steel and extend the service life of the mould.