Plaxis(FEM) software was used to simulate a ultra-deep excavation constructed by top-down method in Shanghai. The paper analyzed the influence of insertion ratio of underground diaphragm wall,number of pile and temporary support on deformation respectively.It analyzed the general deformation law of calculation result,and got the general deformation law of ultra-deep excavation and the control points of deformation. The conclusions can be used for the deformation prediction and design optimization of ultra-deep excavation.