This study investigates the influence of thermal treatment on rockburst in granite caverns through true-triaxial compression tests on pre-heated granite samples. The results show that the uniaxial compressive strength and elastic modulus of granite first increase and then decrease with increasing temperature, reaching their maximums at 200 °C and sharply decreasing at temperatures from 400 to 600 °C. The density and P-wave velocity decrease, while the peak strain increases with temperature. The main failure mode is X-shaped shear-tension failure at 25 and 200 °C, and single-slope shear failure at 400 and 600 °C. Thermal treatment exhibits a slight effect on the rockburst incubation process in granite caverns, with the required stress for rockburst decreasing when the temperature increases or decreases from 200 °C. The higher the temperature, the lower the required stress. The mechanism of thermal treatment on rockburst in granite caverns is attributed to the strengthening effect caused by water loss and the weakening effect caused by thermal expansion cracking. The study provides theoretical guidance for the stability analysis and rockburst prevention in temperature-affected granite caverns.This study investigates the influence of thermal treatment on rockburst in granite caverns through true-triaxial compression tests on pre-heated granite samples. The results show that the uniaxial compressive strength and elastic modulus of granite first increase and then decrease with increasing temperature, reaching their maximums at 200 °C and sharply decreasing at temperatures from 400 to 600 °C. The density and P-wave velocity decrease, while the peak strain increases with temperature. The main failure mode is X-shaped shear-tension failure at 25 and 200 °C, and single-slope shear failure at 400 and 600 °C. Thermal treatment exhibits a slight effect on the rockburst incubation process in granite caverns, with the required stress for rockburst decreasing when the temperature increases or decreases from 200 °C. The higher the temperature, the lower the required stress. The mechanism of thermal treatment on rockburst in granite caverns is attributed to the strengthening effect caused by water loss and the weakening effect caused by thermal expansion cracking. The study provides theoretical guidance for the stability analysis and rockburst prevention in temperature-affected granite caverns.