We studied the relationship of humidifying deformation and water immersion content from the unsaturated to the saturated states and analyzed the factors influencing humidifying deformation in water immersion of compacted loess. Humidification axial strain was mainly affected by deviatoric stress, and the influence was significant. We studied the deformation characteristics of compacted loess under water immersion using a CT-triaxial wetting collapsibility test system. Our test results demonstrate that under certain environmental conditions, changes in water content may cause wetting deformation, which exhibits a large impact on the structural characteristics of soil samples. A relationship between the initial state of water content and the water content state under constant stress was established. The results demonstrated that the expression characteristics of humidification level parameters were consistent with the evolution characteristics of structural parameters. This provides a basis for the establishment of a soil strain damage model and quantitative structural indexes. © 2020, Springer Science+Business Media, LLC, part of Springer Nature.