Abstract: As urban development extends to underground space gradually, more and more deep foundation pits with complex surroundings, more nearby buildings and deep excavation occur. The reinforced concrete circular bracing system has the advantages of reasonable load transfer, small deformation and convenient earth excavation, and it is widely used in urban deep foundation pits. Based on the experience of design and construction of foundation pits, some important problems needed to be considered during design and construction of foundation pits are analyzed, such as bracing stiffness, layout of corner bracing, calculation of bracing columns, crack control and static detonation of bracing system. The reasons of the difference of deformation between design and monitoring values are discussed. The results have direct reference value for the design and construction of reinforced concrete circular bracing system in urban deep foundation pits.