Based on the Xi'an XingFuLinDai Foundation pit Project, a three-dimensional numerical model of the foundation pit is established by ABAQUS finite element software in this paper.The influence of pile distance to pile diameter ratio on the internal force and deformation of the supporting structure is studied; the sensitivity analysis of each supporting parameter that affects the internal force and deformation of the supporting structure is carried out, and an orthogonal experiment is designed based on this, the optimized design of sparse piles and strong anchors based on the project is proposed. The conclusions are as follows: (1) As pile distance to pile diameter ratio increases, the internal force of the supporting pile and the horizontal displacement of the top of the supporting structure also increase, and the change in the pile distance to pile diameter ratio affects the lower half of the pile. The influence of internal force and the deformation of the second half of the excavation of the foundation pit is more significant. (2) The sensitivity analysis of supporting parameters shows that the order of the sensitivity of supporting parameters to the internal force and deformation of the supporting structure is as follows: supporting pile distance-diameter ratio> anchor cable prestress> anchor cable vertical spacing> anchor cable length >The inclination angle of the anchor cable placement. (3) Based on the sensitivity analysis of support parameters, the sparse pile and strong anchor support structure under the current engineering background is optimized, and it could provide reference for similar projects.