Abstract: The evaporation of LNG is one of the important factors that influence the transportation safety of tank containers, but the characteristics of dynamic evaporation during shipping have not been clarified yet. The prototype test is the research method that can best reveal the characteristics of dynamic evaporation. However, the loading capacity of existing test methods and equipment cannot meet the requirements of prototype test. Hence, a prototype test system of dynamic evaporation was designed based on the 40 ft (1 ft = 0.304 8 m) LNG tank containers, and a large-tonnage motion simulator platform with single degree of freedom was built. Then, the prototype loading on the physical substructure was realized by motion loading, and the boil-off gas velocity, which served as the indicator to characterize the intensity of evaporation, was measured by an intelligent gas measurement system in real time. As shown by the actual measurement with this system, the proposed prototype test system can be used for the systematic research on the characteristics of dynamic evaporation of tank containers, and ship motion can facilitate the LNG evaporation in tank containers. Generally, the research on the characteristics of dynamic evaporation is of great significance to the safety evaluation of LNG transportation by tank containers.