The treated tail water of the sewage treatment plant of the textile printing and dyeing environmental protection comprehensive treatment center in Chaoyang District, Shantou City, Guangdong Province is finally discharged into the sea area of Guang"ao bay through the penstock. The sea area section of the sea drainage pipeline is 1021m long and is connected with DN800 ~ DN1000 solid wall PE pipe and flange. Considering the actual situation of the project, the safety and reliability of the design scheme were ensured by selecting appropriate pipes and interfaces, slotting laying after steel sheet pile support in the wave breaking area, and pipe laying ship method in deep water area. During the construction process, the trench excavation, marine transportation, counterweight setting and sinking laying were mainly controlled, and emergency plans such as typhoon prevention, ship collision prevention and anti fog were formulated to ensure the safe implementation of the project.