Abstract: Based on the theory of the humidity stress field, some swelling pr oblem of the underground chamber under the action of water is simulated effectiv ely by means of three-dimensional finite element numerical simulation. It shows thats the damage action of water and the self capability of swelling ro ck are important factors influencing the stability of underground chamber by analys is of some chamber supporting scheme. The mechanical effect of interaction betwe en water and swelling rock and effect of support is deeply known. At prese nt, the research can be provided as an efficient reference to the design and con struction for some underground chamber projects.