The work boats capable of working in inland waters will have to face the following problems: narrow channel; too many bridges; piers with too little spacing; bridge height is very limited and so on. To solve this problem, This article describes a special engineering assembled ship and its assembly method. The ship has a modular design and it can be assembled in a self-floating state. Not only that, The ship integrates two functions: based bed leveling and immersed tube installation. The ship not only simplifies the types of construction vessels, The design concept of assembly also has broadened the scope of application in inland waters.