Abstract: In order to study the variation characteristics of the deformation and water content of unsaturated soils under hydro-mechanical effects, the unsaturated soil triaxial apparatus is used to carry out suction equilibrium, isotropic consolidation and triaxial shear tests on unsaturated clay. The variation of deformation and water content of expansive soils is real-time monitored, and that with time under hydro-mechanical action is comprehensive analyzed. Based on the "double-pore structure" model, the mechanisms of soil deformation and water content variation under hydro-mechanical action are revealed. The results show that in the process of suction equilibrium and isotropic consolidation, the deformation and water content of unsaturated soils vary with time. The deformation reaches the equilibrium in a relatively short time, but the water content reaches the equilibrium in a longer time. In the triaxial shear process, the amount of shear deformation and the discharge of pore water are basically linear with time. With the increase of suction, the time for the moisture content to reach the equilibrium increases, which has few effects on the time for the deformation to reach stability. The increase of the net confining pressure increases the time for water content to reach the equilibrium, but it has few effects on the time for deformation to reach stability. The "double-pore structure" model is modified, and the external force basically only affects the inter-aggregate pores. The variation of water content causes the rearrangement of soil particles, and then affect the macropores in the soil. The migration rate of pore water between aggregates is relatively large, and the migration rate of pore water between particles is relatively small.