Under 1MPa confining pressure, a series of CT scanning tests were performed on frozen Lanzhou loess with different temperatures under triaxial loading condition. The soil damage variable expressed by CT number was obtained and the following conclusions can be drawn. At the beginning of loading confining pressure, the specimen is compressed along the radial direction, leading to axial elongation of the specimen; the duration of elastic deformation of the specimen at low temperature is more longer than that at higher temperature, i.e., at -2.3  ℃, when it reaches a strain of 0.32%, the specimen will yield to the plastic deformation, and at -7  ℃, it is necessary to reach a strain of 1.33%. The stage of plastic deformation of the specimen will last for a long time, even if the specimen has reached 20% of axial deformation, the specimen cross-sectional area will significantly increase, with deviatoric stress increasing continuously. The total damage amount of each specimen is lower than 0.1, much smaller than that under uniaxial stress state. So the confining pressure is able to "endure damage". With the increase of strain and deviatoric stress, damage amount is increasing. Specimen at low temperature requires deviatoric stress more than that at high temperature for reaching the same damage.