Abstract: The subway of Line 10 at Liyang Road has an interchange station with the opening subway of Line 4 at Hailun Road. The site is underlain by several different sandy-silt layers and double-confined water layers, and the double-confined water gets together at the south side of the interchange station, which causes a lot of technical problems, such as pit excavation, environmental impact and protection of the safe operation of Line 4. For this project, the characteristics of different ground-water treatment methods are analyzed, and the horizontal sealing technology is proposed. The location and thickness of the horizontal sealing layer are analyzed and their effects on pit deformation and its surroundings are studied through theoretical analysis and three-dimensional finite element simulation, and the optimization of the horizontal sealing measure is carried out. The feasibility is proved by means of the monitoring results during excavation, and the results are useful to similar projects.