TNM titanium aluminum alloy has low density, excellent high temperature mechanical properties and good high temperature deformation ability. It is a high-profile new generation of aero-engine low-pressure turbine blade material. The current service temperature is about 750 °C. In this paper, the high temperature exposure oxidation experiment of TNM alloy in the air is carried out. The surface morphology and oxide composition of the sample are analyzed by scanning electron microscope (SEM), energy spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The oxidation conditions within 200h at 700 ℃ and 760 ℃ were studied respectively. The results show that the main surface oxidation products at 700 ℃/200 h are Al2O3; the main surface oxidation products at 760 ℃/200 h are TiO2.