Abstract: The background of this paper is the excavation at Guangxi University Station for Nanning Orbit Transit Line 1.It analyzes the dynamic monitoring data during construction. It summarizes the deformation behavior of diaphragm wall and surrounding surface subsidence. The data shows that the subsidence due to excavation is relatively small and its main influence range is 0 to 2H(H is the excavation depth).The position of the maximum settlement value is at 0.5H to 0.7H away from the diaphragm wall. The influence range of subsidence deformation is extended to 4H away from the edge of excavation. According to the deformation behavior, the subsidence estimation curve and environment protection degree division to excavations in gravel area are obtained.