Ti₂AlC is considered to be one of the compounds with the best antioxidant properties in MAX phase materials, with potential application prospects in the field of high-temperature structural materials and high-temperature antioxidant protective coatings. However, the low hardness and strength of single phase Ti₂AlC limit its wide application in the field of high-temperature material. In order to improve the properties of Ti₂AlC, Ti₂AlC-20%TiB₂ (in volume) composites (referred to as Ti₂AlC-20TiB₂) were synthesized by the in-situ solid-liquid phase reaction/hot pressing method. Besides, the high temperature oxidation behavior in the temperature range of 1000-1300 ℃ was studied, and the oxidation resistance mechanism at high temperature was analyzed. The results show that the oxidation kinetics of Ti₂AlC-20TiB₂ composites is logarithmic, exhibiting superior oxidation resistance compared to single phase Ti₂AlC. Below 1200 ℃, the oxide scale is mainly composed of an inner layer of Al₂O₃ and an outer layer of TiO₂, while the outer layer of oxide scale is a mixture of TiO₂ and Al₂TiO₅ at 1300 ℃. The Al₂O₃ protective layer formed in the composite is denser than that in single-phase Ti₂AlC, which is the key to its excellent antioxidant performance. The addition of TiB₂ reduces the grain size of the material and increases the number of grain boundaries for short-circuit diffusion, which facilitates the selective oxidation of Al and accelerates the formation of Al₂O₃ protective layer. Additionally, B₂O₃ produced during the oxidation of TiB₂ can effectively fill the micropores and repair microcracks, thereby preventing the internal diffusion of O and further enhancing the antioxidant properties of the composites.