With the continuous emergence of large and complex foundation pit projects, geotechnical engineering has put forward higher requirements for the accuracy of design. The advantages of BIM technology, such as systematization, visualization, and informatization, can improve the accuracy of design and meet the needs of geotechnical engineering design. Based on a deep soft soil foundation pit project in the Nanjing area. A new type of retaining pile and variable stiffness support system are adopted, and we use BIM software to conduct 3D modeling to form a BIM model of the foundation pit engineering, pre-adjust the unreasonable design, avoid unnecessary construction changes and construction problems, and improve It improves the efficiency of geotechnical engineering design and construction, realizes the dynamic design of geotechnical engineering, and has great significant value for the application of BIM technology in the design of new geotechnical engineering processes.