Abstract: Combined with the application a new type of composite supporting system in a deep excavation engineering in Beijing, the supporting form and structure features of the system are analyzed and introduced. Theoretical calculation, numerical simulation and field monitoring analysis of the support system are carried out. The result shows that the support system successfully solves the technical difficulties of deep foundation pit, such as deep artificial fill, small space and complicated surrounding environment. It can effectively control the deformation of the foundation pit, shorten the construction period, save the cost of the project, ensure the safe use of the foundation pit engineering, and provide an effective reference experience for similar projects.