In order to improve the corrosion resistance and wear properties of the micro arc oxidatin (MAO) coatings on TC4 titanium alloy in the marine environment. The TaC doped MAO coatings were 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 were characterized and analyzed by SEM,EDS and XPS, The thickness, roughness, hardness, wear resistance and corrosion resistance of the three MAO coatings were compared and evaluated. The results showed that, by adding TaC microparticles to the base electrolyte, TaC and Ta2O5 were present in the MAO coating on titanium alloy. Compared with the MAO coating without TaC, the surface morphology of the coating with TaC was dense and the hardness was increased by about 83.2%; The friction coefficient of the coating in the simulated seawater decreased from 0.2 to 0.148, changing from serious abrasive wear to slight adhesive wear; The corrosion current density of this coating decreased by two orders of magnitude. The newly designed MAO coating has effectively improved the applicability of the titanium alloy in the marine environment. 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 has been revealed.