FLAC^3D is an important numerical simulation method in analyzing the settlement and deformation of adjacent structures caused by foundation excavation, but its pre-processing modeling is difficult to establish complex numerical models. This paper is based on the foundation excavation process. In order to compensate for the weakness of FLAC^3D pre-processing, Rhino software was first used for modeling, and then the Griddle plug-in was used to divide the model to generate grid files that could be imported into FLAC^3D. In this paper, based on the excavation project of the main foundation pit of the South Third Ring station of Xuzhou Metro Line 4, AutoCAD, Rhino, Griddle and FLAC^3D software was used to establish the numerical model of the foundation pit supporting structure rapidly, the adjacent main body of the existing metro station, and the stratum under complex working conditions respectively, providing modeling experience for the rapidly establishment of the numerical model under complex working conditions.