An ideal plane strain model has been set up, by using ANSYS finite element analysis software, to achieve a continuous construction of the foundation pit excavation support by killing the soil or activating the support units. An analysis has been made of the relevant factors, which affect the stability of the pile anchor supporting structure, by changing the support pattern in computational models. A comparison has been made between the calculation results of the deformation of foundation pits and the actual monitoring data under various operating conditions, thus verifying the feasibility of the finite element calculation model with a further guidance for engineering practice.