As a new self-healing agent, Ti₃SiC₂ was added into yttria-stabilized zirconia (YSZ) thermal barrier coatings. By atmospheric plasma spraying (APS), thick coatings were prepared using an YSZ–Ti₃SiC₂ mixing powder. To observe oxidation and self-healing behavior, cracks were prefabricated on the surface of YSZ–Ti₃SiC₂ coating by uniform external load. The prepared samples were then isothermally treated at 1050℃ in air. The phase and morphology evolution of the coatings, as well as the self-healing behavior were investigated via several analyzing methods. The results showed that a part of Ti₃SiC₂ was decomposed into amorphous SiO₂ and TiC after spraying and a double layered structure composed of a TiO₂ outer layer and a TiO₂+SiO₂ inner layer was formed after isothermal treatment. In the process of self-healing, oxidation of the healing agent in the coating led to the growth of silicon oxide and titanium oxide in the cracks. These oxides gradually filled the cracks due to the diffusion-controlled oxidation. Meanwhile, the compressive stress induced by the volume expansion due to SiO₂ and TiO₂ growth in the crack enhanced the healing effect. Eventually the prefabricated cracks were healed.