Taking the drainage system of Xintang Town as an example, combined with the strategic goal of building a national new smart city in Guangzhou and the needs of realizing the intelligent construction of municipal drainage system in Xintang Town, this paper introduces the application of smart water in "squeezing out water and increasing concentration" of sewage pipe network system and flood control and drainage prediction of rainwater system. The online real-time monitoring of the water level, water quality, flow and external water intrusion of the sewage pipe network system is of great benefit to improve the operation efficiency of the sewage plant. The real-time monitoring and early warning of the waterlogging prone points of the rainwater system and the water level of the external River are carried out, and the urban waterlogging risk early warning system is constructed to avoid disasters, so as to realize the intelligent operation and management of the drainage pipe network system as specialization and refinement.