Abstract: Dry dock design is very important and difficult for an immersed tunnel, as the design scheme will directly affect the construction cost and timeline. Using the design of the dry dock for the Fenjianglu South Extension Project in Foshan as an example, this paper illustrates a new scheme for a side-built dry dock with the dry dock and main body foundation pit constructed simultaneously and the segment prefabrication and major structure on the bank completed at the same time. This new scheme solves problems concerning the construction site of large-scale dry docks, overcomes the shortcomings of the long construction period required for an axis-line dry dock, and eliminates the high costs of an independent dry dock.