Abstract: Based on a deep foundation pit project under the unbalanced earth pressure in Guangzhou, selection of supporting structures is comparatively analyzed using three-dimensional numerical calculation. Through the combined system of large-diameter concrete piles and concrete corner support or truss support, the deformation generated by the unbalanced earth pressure at the north and south sides of the foundation pit is coordinated. The security of foundation pit and surrounding environment is ensured. The monitoring data and the deformation characteristics of the retaining structures show that the combines support achieved a good effect.