Abstract: Through studying long foundation pits, a simplified computing model of diaphragm wall is established to improve model’s computing efficiency. In the model, the hyperbolic nonlinear spring element was adopted to simulate the elasto-plastic interaction between the wall and the foundation soil. The model’s calculation width is supposed to be that of the diaphragm wall segment and its six kinds of boundary conditions are determined according to the locations of the segments’ junctions and the way they joint. Furthermore, soil stratifying and the supports’ pre-force are considered. The model’s computed results agree quite well with the in-place data by computing the diaphragm wall of one foundation pit in Tianjin. It gives a simple and effective computing method for simulating the process of foundation pits’ excavation and for forecasting diaphragm walls’ deformation.