Ceramic coatings were prepared in situ on the surface of TC4 titanium alloy by means of micro-arc oxidation(MAO) technology, and the coatings were sealed with sodium silicate aqueous solution. The phase composition of the coatings was analyzed by X-ray diffractometer(XRD), and the surface morphology of the coatings were observed by scanning electron microscope(SEM). Through the bonding tensile test, the bonding strength between MAO coating and substrate before and after sealing was compared. Using high temperature oxidation experiments, the high temperature oxidation resistance of the TC4 substrate and coating samples before and after sealing was investigated. The results show that the bonding strength between MAO coating and substrate is high. After sealing and oxidation at high temperature for 100 h, the bonding strength of the coating decreases to 4.29 MPa. Compared with the TC4 substrate, the high temperature oxidation of the micro-arc oxidation coatings is lower, and the high temperature oxidation resistance is significantly improved. The sealing treatment improves the compactness of the micro-arc oxidation coating, so that it can better prevent oxygen from penetrating the coating into the substrate, and further improve the high temperature oxidation resistance of the coating.