Abstract: In order to better understand the mechanical behaviors of the supporting structure of the deep foundation pit, a tri-parameter foundation model is used, according to different stress patterns of the supporting structure, to build a computational analysis model with consideration of the influence of the adjacent building. In this computational analysis model, the additional stress caused by the adjacent building and the pressure of a certain width soil between the supporting structure and the adjacent building are considered. The matrix expressions for the internal forces and the deformations of the supporting structure are derived by using the pile discrete method and the matrix transfer method, and the semi-analytical solution for the supporting structure is obtained. For an excavation project, the influences of the additional stress caused by the adjacent building and the distance between the supporting structure and the adjacent building are analyzed, this method is verified, and it can be used for the design of this type of supporting projects in dense urban areas.