Abstract: During the excavation of rock tunnels, the acquisition velocity and accuracy of joint information will affect the safety of the project directly. The three-dimensional noncontact measurement software 3GSM is employed to obtain digital images which characterize the macrostructure of rock mass in short time, then the information of spatial distribution geometric shape of joints is extracted. The rock mass 3D analysis system GeoSMA-3D is adopted to identify the key block of surrounding rock. At the same time a model is developed by using the discrete element method program-3DEC and the FISH language which is embedded in 3DEC. The motion and falling modes of the rock during the excavation are studied. The whole process of motion and deformation of the rock mass is recorded and analyzed. Finally, the numerical results are employed to guide the project construction.