This paper aims to solve the negative effects of the large unfrozen water content and high compression of high warm and frozen soil on the stability of roadbed. In this study, by taking the silty clay in the permafrost regions of Qinghai-Tibet Plateau as the research object, 15% ordinary Portland cement, high-performance Sulphoaluminate cement, and (ordinary Portland cement+high-performance Sulphoaluminate cement) were prepared as samples at negative temperature. The oven drying method, TDR (time domain reflectometry) technique, X-ray diffraction, scanning electron microscopy (SEM), and thawing compression test were adopted to analyze changes of the total water content, changes of unfrozen water content, and the phase composition of the soil with the addition of soil stabilizers, as well as to compare the solidification effects of different soil stabilizers. MATLAB was used to develop CURVEEXTRACT image analysis system to deal with SEM image, which was then imported to the Image-ProPlus6.0 (IPP) software to analyze the characteristics of micro pore distribution, morphology, and directivity of high warm and frozen soil before and after solidification. The relationship between macroscopical and microcosmic before and after solidification was established based on the relationship between compression property and pore orientation fractal dimension. Results show that adding soil stabilizer could reduce the total water content and increase the unfrozen water content in the soil samples. After solidification, soil particles became closer, the pore area of the soil decreased, and the pore transformed from narrow to equiaxial. There was a good linear relationship between the pore directional fractal dimension (D_f) and the coefficient of thaw compression (a_v). The better the curing effect was, the smaller the D_f was, and the smaller the corresponding a_v was.