As a joint inspection building for sea route, the project proposes the concept of "baige zhengliu- fierce races for winning " of Dragon Boat (a traditional transportation tool), and creates a building with great movement and tension with triangular and inclined geometry language, which runs through the architectural form, facade, roof and interior forming a coherent indoor and outdoor visual effect. Due to the limitation of site conditions, the project adopts the strategy of "vertical ports" to separate the entry-exit functions and flows by stacking the layout, tremendously improving the efficiency of customs clearance.