Abstract: The completely deteriorated cement soil samples were prepared by simulating the formation process of cement soil in the corrosive site, and a series of indoor permeability tests are conducted in order to study the evolution laws of permeability of cement soil with deterioration degree. The results show that the effect of soaking solution on the permeability coefficient of completely deteriorated cement soil is negligible, and it can be immersed by the corrosive solution to accelerate the complete deterioration and shorten the sample preparation time of completely deteriorated cement soil. However, the concentration of solution is too high, the surface of cement soil sample may fall off, which affects the quality of sample preparation. The permeability coefficient of completely deteriorated cement soil is related to the cement ratio, which decreases with the increase of cement ratio. Under the experimental conditions, the permeability coefficient of completely deteriorated silt cement soil is completely close to that of silt, and the permeability coefficient of completely deteriorated kaolin cement soil is less than that of kaolin. The permeability coefficient of completely deteriorated cement soil is much larger than that of cement soil. The research results can provide a theoretical basis for the design of cement soil waterproof in the corrosive site.