Abstract: The physical nature of frozen soil damage is analyzed. A series of CT scanning during the uniaxial compress test process is conducted on an enhanced triaxial system which works together with the CT system. According to the test results, the yield strain, damage strain critical value, and failure strain critical value of the frozen remolded Lanzhou loess are obtained. Then, the plastic strain is used to describe the damage threshold value. The lower the temperature, the larger the damage threshold value. In the end, the CT value is used to define damage variable, and the damage evolution law is derived based on the results of CT scanning tests. A damage potential function suitable for frozen soil is proposed.