Base on the project of foundation pit supporting system of south-to-north water transfer project in yellow,the paper made the analysis on the stress and displacement by means of theoretical arithmetic,numerical simulation and monitoring data. The conclusion is as follow: the stress of the diaphragm wall is given priority to with pressure,tensile stress and shear stress are very small,and stress level is far lower than the design value. And compare the results of theoretical value,simulate value and measured value. The theoretical value is larger than the simulate value and measured value,while the simulation results are similar to the measured value,but slightly lower than the measured values.