Excavation leads to generate critical slip surface of soil.By MIDAS finite element calculation software, numerical analysis was carried out on the wanda square foundation pit engineering.It summarizes the hardening soil model parameter selection rule.Taking Wanda plaza deep foundation pit engineering as example, the calculation of horizontal displacement monitoring curve of soil analyzed the deformation law ofhorizontal displacement of soil.Through the analysis of the data, analysis of the numerical analysis of spatial effect of foundation pit excavation, combining with the working condition of SMW method analysis of supporting and double row piles under the support of the law of the spatial effect ratio.