As a method to control deformation, shaped steel-reinforced cement-soil composite retaining wall could be used in excavation engineering. Based on the analysis of the calculation method for the deformation of the cantilever structure, it is pointed out that the bending stiffness of a composite wall is the key factor. However, the load sharing of the steel and cement-soil is varied with applied load, so the bending stiffness is uncertain under external load. To analyse the deformation characteristics of a composite retaining wall, a three-dimensional model was established for numerical simulation based on a case study of a 5.4 m deep excavation in Shanghai. It is found that the maximum displacement appeared in the middle of the structure, which limited the displacement at the top. Also, the cement-soil can share the load and contribute to the deformation control. It is economical to control the replacement ratio of the cement-soil within the requirements,and more favorable to densely arrange the front rows of H-shaped steel.