Abstract:Using the numerical simulation software, the stability of underground excavation with different rock mass material was studied. Conclusions can be drawn as follows: (1) due to the plastic deformation, the value of the maximum principal stress surrounding the tunnel is highest, flowed by elastic-plastic material, and elastic-brittle-plastic is low. (2) the minimum principal stress magnitude in the three materials is similar and the value close to 0. (3) the characteristics of displacement in rock mass corresponding to excavation is also basically similar. (4) the stability factor of failure rock mass surrounding excavation of elastic material is also less than 1.0, elastic-plastic and elastic - brittle - plastic large than 1.0. Using numerical simulation software to study the stability of tunnel, the selection of different materials should pay attention to the appropriate value。