Abstract: The successful experience of diaphragm wall and internal bracing system for deep foundation pit in deep silt layer is introduced. Some technical measures for construction of diaphragm wall, dewatering and soil excavation are discussed. In the construction, the monitoring technology and advanced information technology are emplyed to ensure that the construction of the foundation pit is in a controlled state. The design and construction experience has certain reference meanings for the construction of deep foundation pits in the region.