Abstract: With the uniaxial and triaxial compression tests of the water-cooled granite samples under high temperature, the mechanical properties of the water-cooled granite under high temperature within 800°C against the temperature change and the confining pressure are determined. The experimental results indicate that: (1)The threshold for the effect of high temperature heating and rapid cooling with water on the mechanical properties of the granite is 400°C. (2)Under the same temperature condition, the peak deviator stress and the peak strain increase with the increase of the confining pressure. The elastic modulus increases first and then decreases with the increase of the confining pressure. (3)In uniaxial tests, when the temperature is lower than 400°C, the rock samples will be in a form of composite failure. With the increase of the temperature, the damage morphology changes to a tensile failure. While in the triaxial test, the rock samples all have the shear failure.