The navigation demand of small-scale LNG vessel in the river is already put on the schedule in China. According to the navigation management regulation of LNG vessel for the sea port, it is impossible for the small-scale LNG vessel to sail in the river. Combining with the navigation management status of liquid bulk vessel on river, this paper introduces the reason of traffic control on sea port LNG vessel navigation, analyzes the fatalness of LNG vessel and LPG vessel, discusses the potential risks that small-scale vessel sails in the river and the corresponding measures, and gives a conclusion that small-scale LNG vessel with double hull and double bottom may sail in the river normally without special traffic control.