Abstract: For a deep foundation pit in Lanzhou, its support and dewatering are designed according to the engineering geological and hydrological conditions. The measures of well-point dewatering and organized drainage are adopted, and real-time monitoring of horizontal and vertical displacements of supporting structures and settlement of buildings around the foundation pit is made. The monitoring results show that under the dewatering scheme the displacement of the supporting structures and settlement of surrounding buildings are well controlled. It may provide valuable experience for the construction of similar projects in Lanzhou.