In order to improve the corrosion resistance and wear properties of the micro arc oxidatin (MAO) coatings on Ti-6Al-4V alloy in the marine environment, TaC-doped MAO coatings are prepared by adding different concentrations of TaC microparticles with a particle size of about 1 μm into the silicate-based electrolyte. The morphology, elemental distribution and composition of the coatings are characterized and analyzed by SEM, EDS and XPS. The thickness, roughness, hardness, wear resistance and corrosion resistance for each of the three MAO coatings are evaluated and their corresponding values of these coatings are compared with each other. The results show that by adding TaC microparticles into the base electrolyte, TaC and Ta₂O₅ are present in the MAO coatings on titanium alloy. Compared with the MAO coating without TaC, the surface morphology of the coating with TaC is dense and the hardness is increased by about 83.2%. The friction coefficient of the coating in the simulated seawater decreases from 0.2 to 0.148, changing from serious abrasive wear to slight adhesive wear. The corrosion current density of this coating decreases by two orders of magnitude. Furthermore, by constructing the wear and corrosion failure model of the MAO coatings in the simulated seawater, the internal mechanism of doping TaC microparticles into the MAO coating to improve its corrosion resistance and wear resistance is revealed.