The treatment of underground water is very important in opencut Metro construction in waterrich sandy stratum. The most common and effective method, dewatering, is the key to the project. The dewatering tial, design optimization and dewatering are analyzed. The successful application of design and construction of dewatering of deep foundation pits in Fengbo Field of Beijing Metro line 15 is presented in detail. The paper can provide references for similar projects in the future.