Abstract: Taking the Pile-Beam-Arch (PBA) construction of subway station as the research object, the influence of different section construction on the maintenance pile and the law of the variation of the lateral displacement with the excavation depth are discussed. By comparing and analyzing the influence of bracing and non-bracing on the internal force and displacement of the retaining pile in the process of excavation of soil under the plate of different sections, the two-dimensional analysis of soil under the plate of PBA (Pile-Beam- Arch) method in Xinbai subway station is carried out by using GTS Software and the distance and position of steel braces are determined.