Abstract:The medium triaxial compression tests of air-dried and saturated soft rock fillers were carried out respectively, and the deformation laws of materials under different confining pressure conditions were obtained. Using double-line method, the strain difference of air-dried and saturated materials under the same axial deviatoric stress is taken as its wetting deformation, and the influence of confining pressure on its variation law is mainly analyzed. The following laws are obtained: ①Compared with air-dried state, confining pressure has a greater influence on the deformation law of saturated state fillers; ②The development of wetting deformation is divided into two stages, in which the wetting deformation value develops to the critical value as the boundary value, and the wetting deformation increases significantly in the latter stage;③In the initial stage before the wetting deformation develops to the critical value, the confining pressure is not the main influencing factor, and the influence of the confining pressure on it is obvious in the second stage;④The regression formula of wetting deformation analysis is given and verified.