Abstract: The warm and humid climate in the Qinghai-Tibet Plateau region has increased the risk of disasters such as widely distributed red clay landslides. This paper takes the red clay in the Nangqian area of the Qinghai-Tibet Plateau as the research object and obtains the shrinkage characteristics of two initial dry density red clays under freeze-thaw cycles through the direct measurement method. The results show that the freeze-thaw cycle causes the initial structure of the soil to be destroyed and reorganized, resulting in volume shrinkage. After the number of freeze-thaw cycles N=4, the volume of the sample shows a recoverable expansion and contraction change. With the increase of freeze-thaw cycles, the shrinkage characteristic curves of the two initial dry density specimens gradually shift upward, the slope of the proportional shrinkage section significantly decreases, and the curves tend to coincide at N=5 and N=7. Meanwhile, the fitting parameters a and b of the Fredlund model have smaller numerical fluctuations when N=7, indicating that the influence of freeze-thaw cycles on soil shrinkage tends to be stable when N=7. The freeze-thaw cycle causes structural shrinkage segments in the two initial dry density specimens, and the structural limits are approximately 0.8 and 0.68. The research provides a theoretical basis for the prevention of freeze-thaw disasters in plateau areas.