Abstract:The complete process of excavation,deformation and supporting of a deep tunnel was simulated with three physical models of the tunnel performed with a true triaxial test. During the experiment,the tunnel was excavated after a certain confining pressure was exerted on each model,and the supporting device of air bag was created to provide support pressure for the tunnel. The techniques of digital picture deformation measurement were applied to the processes of high definition color pictures of the model,through the displacement field of the rock surrounding,the tunnel could be obtained. Based on the analysis of the displacement field,the relation of support pressure and stability of the surrounding rock mass in deep tunnels was achieved,which would provide the theoretical and technical basis for stabilizing the deep tunnels.