According to the analysis method by Lizheng software and actual pit control variables to analyze and calculate the optimal solution,the results of horizontal displacement of the scheme are obtained. By changing the diameter of the pile,we can analyze and calculate the detailed parameter scheme that can be more economical under the premise of safety requirements and specifications. Then,the optimal scheme is simulated by finite element method,and the displacement analysis and settlement analysis are carried out to verify the rationalization. Conclusion:with the increase of excavation depth,the settlement of pile increases at first and then decreases,while the settlement of soil decreases gradually. The horizontal displacement of the pile and soil is uniformly distributed from top to bottom,and then the maximum horizontal displacement occurs at the top of the pile.