According to the granite formations of deep wells and ultra-deep drilling, through the measurement of the longitudinal wave velocity after the granite heating and conventional tri-axial compression tests, and based on the experimental results, the study is made on the longitudinal wave velocities of granite by different temperatures heating and macro mechanical properties under tri-axial compression stat. The analysis is made on the relationship between the granite longitudinal wave velocity, peak stress, elastic modulus, peak strain and the temperature; at the same time, the granite macroscopic failure form under the condition of tri-axial compression are summarized. The results show that, after heating and cooling, granite longitudinal wave velocity is decreasing with increasing temperature; meanwhile, under a constant confining pressure, when the temperature changes from 20℃ to 200℃, the peak stress, elastic modulus, peak strain tended to increase with the temperature increasing, but when the temperature changes from 200℃ to 400℃, these mechanical parameters is decreasing. Temperatures can make the water content of rock gradually decreases, and because of different thermal expansion of rock internal mineral compositions, the additional thermal stress inside the rocks is generated, thereby the initial crack inside the rock will have propagation and coalescence or new cracks generate to affect the stability of the borehole wall and the surrounding rock.