Abstract: In response to the issue of boreholes shrinkage crossing swelling rock in coal mine, in this paper，based on the humidity stress field theory, analytical solution of boreholes displacement considering humidity damage and expansion has been deduced by using finite element analysis program and introducing humidity corrected coefficient ψ(w).So，the effects of the humidity field and stress field on boreholes shrinkage are systematically studied and analyzed by the software ANSYS and similar model experiment. The results show that with the water ratio of surrounding rock increasing, the wall displacement of boreholes is nonlinearly growing; the wall is“dumbbell-shaped”with two ends crude and intermediate fine; the maximum radial displacement is in the central wall of the boreholes；the effect of lithology softening resulting from the boreholes shrinkage is obvious；as ground stress increases, the wall displacement of borehole increases linearly but has a small increase；the above two fields have enormous effects on boreholes shrinkage. As far as the degree of influence is concerned， humidity field causes the larger influence, followed by stress field.

Key words: swelling rock, boreholes shrinkage, humidity stress field, similar model experiment