Abstract: To investigate the brittle failure and damage characteristics of water-bearing sandstone under freeze-thaw cycles and impact loads, a systematic experimental study was conducted. First, freeze-thaw tests were performed on sandstone samples with five different water contents (0%, 0.5%, 1.0%, 1.5%, 2.0%) within a temperature range of ±20 °C using a freeze-thaw chamber. Porosity and P-wave velocity of both original and freeze-thawed (then dried) sandstone samples were measured using a mercury intrusion porosimeter and an ultrasonic wave velocity tester, respectively. Subsequently, uniaxial impact compression tests were conducted on the freeze-thawed and dried sandstone samples using a Split Hopkinson Pressure Bar (SHPB) system under an air pressure of 0.3 MPa. Based on the post-peak stage of the stress-strain curves, a brittle failure characteristic coefficient of sandstone was established to analyze the influence of water content variation on brittle failure behavior. Finally, the damage evolution characteristics of sandstone were analyzed by combining porosity, P-wave velocity, and dynamic elastic modulus after impact loading. The results show that under freeze-thaw cycles at ±20 °C, the porosity and P-wave velocity of sandstone at 0% water content showed almost no change. As the water content increased, the porosity of sandstone gradually increased while the P-wave velocity gradually decreased. Compared with the water content of 0.5%, the porosity of sandstone at 2.0% water content increased by 10.39%, and the P-wave velocity decreased by 18.79%. With the increasing of water content, the dynamic peak strain of sandstone gradually increased (water content increased from 0% to 2.0%, the dynamic peak strain increased by 40.35%), whereas the dynamic peak strength, dynamic elastic modulus, and brittle failure characteristic coefficient gradually decreased (at 2% water content, compared with those at 0.5% water content, the dynamic peak strength, dynamic elastic modulus, and brittle failure characteristic coefficient decreased by 40.17%, 52.11%, and 50%, respectively), the brittle failure characteristic coefficient exhibited an exponential decline with increasing water content. The damage in water-bearing sandstone under freeze-thaw cycles and impact loads increased with higher water content, rising from 0.25 at 0.5% water content to 0.71 at 2% water content, with an increase of 184%.