Abstract: A deep excavation project in Chenzhou City is located in the mountainous area of southern Hunan Province. Due to the topographic limitations, the engineering environment of the excavation site adjacent to the high slope is induced. The eccentric effect of the high slope on the deep excavation would result in an additional lateral earth pressure and additional deformation to the supporting structures of the excavation, which has a great influence on the stability and deformation of the deep excavation system. It is necessary to analyze the deformation characteristics of the supporting structure and study the degree of stability affected by the high slope. The MIDAS finite element simulation software was used to establish the numerical model. The deformation data of the supporting pile under the different geometric conditions were analyzed and summarized to obtain the deformation characteristics of the support structure under different conditions. The effect of the stability on the sidewall of the excavated area was evaluated. The results show that during the excavation process, the maximum deformation of the soldier pile appears to be between the two rows of anchors of the supporting structure. Under the same slope height condition, the foundation pit has a critical slope ratio with deformation value changes significantly. The deformation of the supporting structure is more regular under the condition that the slope ratio of the slope is fixed.