With the development of economy and society, the surrounding environment of the new rainwater and sewage pump house is usually complex, and the design is usually implemented by the excavation of foundation pit. The structure of rainwater and sewage pump house is mainly composed of vertical components with the characteristics of no general basement floor design and hard to change support in foundation pit. Combined with engineering examples, the design of foundation pit support and changing support of pump house is analyzed and summarized, which provides a useful reference for the design of deep foundation pit of rainwater and sewage pump house.