Taking the Tianjin Outer Ring Northeast Line Drainage Project as an example, combined with the characteristics of expressways in Tianjin, the division principle of expressway drainage system, and the selection principle of rainwater system design standard are introduced. The design schemes of water outlet, water collection at bridge head sloping point, drainage of the viaduct area, drainage pipeline crossing highway and the other key points are analyzed so as to provide the reference for improving the design of the expressway drainage in Tianjin.