<p>Investigating the freezing properties of the surrounding rock after excavation is critical to frozen rock projects such as tunnel construction in cold regions&#xa0;and underground low-temperature energy storage. Still, the heat conduction of damaged rock in freezing conditions is poorly understood. This work studies the mechanism of heat transfer in granite with varying degrees of damage in low temperatures using thermal conductivity tests in the cooling process combined with the low-temperature digital image correlation strain analysis technique. A CT-scan-based numerical model is also developed to further investigate the temperature distribution influenced by the multiscale fractures embedded in damaged rock. Results show that the thermal conductivity of granite in varying damage states decreases as the fracture density in the identical temperature condition increases, and the distribution of fractures serves as a barrier for the thermal conduction process. As the temperature decreases, the difference in thermal conductivity between granites in varying damage states increases. For granite in a relatively low-damage state, the freezing contraction effect contributed by the closure of microstructures and the enhanced heat-transfer performance of mineral crystals in granite increases the effectiveness of thermal conductivity as the temperature decreases in freezing conditions. However, the effective thermal conductivity of granite in a relatively high-damage state exhibits nearly constant trends as the temperature continuously decreases in the cooling process. The highly distributed multiscale fractures dominate the heat transmission process in this case, and the barrier effects of fracture networks in the highly damaged rock are remarkable, making the thermal conductivity insensitive to the variation of the low temperature.</p>