Abstract: Rock's heat inflation is an irreversible process, and it is influenced by heating history. There is a great characteristic difference during heating and after cooling. Real-time tests on the thermal Iracture failure process of rock under uniaxial compressive and tension loading were carried out, the macro-mechanical properties of rock during thermal fracture failure were analyzed, and the thermal failure mechanism was discussed. According to the thermal fracture mechanism and its strength criterion, the maximum stress of samples was computed, and the results were in good agreement with the experimental.