Foundation pit dewatering is one of the key links in the excavation for building construction by the riverside and is an important factor affecting the construction period and the construction quality of the whole project. The paper introduces the design and implementation process of groundwater treatment for the ultra-deep foundation pit of a high-rise building by Songhuajiang. The selection of the design parameters in the construction process, the construction experience and deficiency are discussed and summarized, which can be reference to the subsequent construction.