Abstract: : For the dispersed soil widely distributed in the Songnen Plain of Northeast China, two schemes involving the incorporation of inorganic cementitious materials were selected for modification. Through porosity tests, direct shear tests, and compression tests under freeze-thaw cycles,the mechanical characteristics of the soil before and after modification were comparatively analyzed, the influence of freeze-thaw cycles on soil porosity, shear strength, and compressibility was investigated. Scanning electron microscopy tests were also conducted to explore the changes in the microstructure of the soil, and the correlation between the mechanical properties and micro-pore structure of the modified soil was analyzed. The experimental results showed that after 7 freeze-thaw cycles, the porosity of unmodified soil increased by 15.7%, the average shear strength decreased by 88.79% after 3 freeze-thaw cycles, and the compression coefficient increased with the number of freeze-thaw cycles. After 7 freeze-thaw cycles, the porosity of the two modified soils increased by only 3.67% and 4.61%, respectively, and the average shear strength decreased by 28.76% and 44.07%, respectively, indicating a reduction in soil compressibility. After modification, the pore structure of the soil became denser, with pores arranged in an orderly manner and enhanced directionality. Probability entropy and fractal dimension had a significant impact on the shear strength of the soil, while the number of pores and porosity had a significant impact on the compressibility of the soil. The macroscopic manifestation was an increase in soil shear strength and a decrease in compressibility, thereby significantly enhancing the resistance to freeze-thaw cycles. It is recommended to adopt appropriate proportions for modifying dispersed soil in engineering projects according to design requirements and soil conditions.