［Purposes ］ This paper aims to investigate the effect of freezing temperature on the degradation characteristics and mesoscopic mechanisms of silty mudstone during the freeze -thaw cycle（FTC）.［Methods］ Triaxial compression tests were conducted on silty mudstone specimens under different freezing temperatures.By analyzing the failure form of the specimens and the scanning electron microscope image of the fractured surface，the strength deterioration characteristics and failure mode of the specimens were obtained.［Findings］ Under the same confining pressure，a decrease in freezing temperature and an increase in the number of FTCs both resulted in an increase in the degradation rates of P -wave velocity and mass.Under the same freezing temperature，an increase in the number of FTCs led to a higher total number of cracks in the specimens and a reduction in the angle of the main cracks，along with a trend of crack expansion and penetration.Under the same number of FTCs，a decrease in freezing temperature resulted in an increased total number of cracks，more detachment of surface fragments，and a reduction in the integrity of the specimens.［Conclusions ］ The freezing temperature plays a critical role in the degradation of specimens during FTC.As the freezing temperature decreases，the strength deterioration of silty mudstone becomes more pronounced，with peak stress，elastic modulus，cohesion，and internal friction angle all exhibiting exponential declines.From a microscopic perspective，this degradation is manifested by an increase in porosity and pore size.