Abstract: With the development of housing construction and subway in our country, the utilization of underground space is increasing steadily, followed by the continuous expansion of the number of foundation pit engineering. The emergence of BIM Technology has brought positive impact on foundation pit construction. Based on BIM technology, the foundation pit construction simulation system was studied. After the information processing of the Revit foundation pit model, the JSON format model was exported. With the JSON model as the core, the web-based foundation pit construction simulation system was built to realize the visual construction simulation of the foundation pit engineering, which was verified by the practice of the World Expo foundation pit project, providing convenience for the project management, speeding up the construction efficiency, and ensuring the safety of construction. The study has reference significance for the application of BIM in foundation pit engineering.