Abstract: The lack of research on the blasting damage-induced cracking characteristics of water-saturated frozen Cretaceous sandstone under in-situ stress has become a technical bottleneck restricting blasting excavation efficiency and harmful-effect control when deep large-scale frozen shafts pass through water-rich sandstone strata. First, the influence of temperature on the blasting dynamic stress field and the distribution characteristics of the static stress field around a blasthole under in-situ stress were theoretically analyzed. Second, a single-hole blasting numerical model was established using the calibrated and validated RHT constitutive model to investigate the effects of in-situ stress and temperature on the blasting damage-induced cracking characteristics of water-saturated frozen sandstone. Finally, a full-section model of blasting excavation in a deep frozen shaft was established to analyze the blasting-induced damage and fragmentation behavior of rock mass under in-situ stress.The results show that the radial dynamic stress is only slightly affected by temperature variation, whereas the circumferential dynamic stress is more sensitive. As the temperature decreases, the peak circumferential tensile stress in the near-blasthole region increases, while the peak circumferential compressive stress decreases. Under hydrostatic in-situ stress, the stress field around the blasthole exhibits a symmetric distribution pattern. The magnitude of hydrostatic pressure affects the static stress level but does not change the distribution pattern. Under non-hydrostatic in-situ stress, the radial and circumferential stress fields show significant directional characteristics. Increasing in-situ stress or decreasing temperature slows the growth rate of the damaged volume and suppresses the development of blasting damage, and the two factors exhibit an interactive and competitive effect on blasting damage. Unidirectional in-situ stress promotes crack propagation along the maximum principal stress direction while suppressing crack development along the minimum principal stress direction. Low temperature reduces the crack propagation range and weakens the directional effect of in-situ stress on crack propagation. In-situ stress has an impedance effect on blasting energy input and damage development, resulting in increased nonuniformity of the fragmentation size distribution and a higher boulder yield in blasting excavation of frozen shafts. The research results have important theoretical and engineering significance for optimizing blasting parameters and improving the efficiency and safety of blasting construction in deep frozen shafts.