Abstract: Considering the Yunnan laterite with different proportions of sand under the initial conditions of the optimum moisture content and the maximum dry density, this paper reveals the relationship between drying-wetting cycles and the changes in physical and mechanical properties of sandy laterite. On the basis of combining geotechnical tests with relevant theoretical researches, the method of Excel is used to analyze the test data. The results indicate that under the drying-wetting cycles, the specific gravity of laterite with different proportions of sand shows a trend from rise to decline; the dry density shows an upward tendency; the shear strength and shear strength parameters have an upward tendency. The tendency is eventually stable after 10 times of cycling. Under a certain number of dry and wet cycle conditions, the greater sanding proportion of laterite comes with the smaller decrease in clay particle. The smaller increase of particle and sand, the smaller numbers of cracks, and the soil samples are more compacted. The largest decline in shear strength and shear strength parameters is the laterite with 15% proportions of sand, and the smallest is the laterite with 10% proportions of sand.