Floating Dock is lower than the water surface, three sides are dock walls, connected to the shore, one side has a dock opening to the water, and a dock door. The dock was originally mainly used for ship repairs. Today's Floating Dock has evolved from an old ship repairing to a harbor where ships can be docked.

The traditional method of building a dock is to first build an enclosure in the water on the shore, drain the water and then dig a foundation pit for dry construction. If the dock is built in a harbor basin, or the foundation is sandy soil with large permeability or a rock foundation with river and sea cracks or the construction and removal of the surrounding area are laborious, the surrounding construction method should not be used.

The dock consists of a dock room, a docking head, a dock door, an irrigation and drainage system, and auxiliary equipment. When the ship is in the dock for repairs, use the irrigation system to pour water into the dock until the water surface is flush with the water surface outside the dock, open the dock door to pull the boat into the dock, close the dock door, and drain the water inside the dock with a drainage system. On the pier on the bottom of the dock.