The utility model relates to an energy supply technical field discloses a LNG storage tank precooling apparatus to realize the automatically regulated of LNG power vessel storage tank precooling, thereby improve the security of whole flow, and effectively improve the efficiency of whole flow. This LNG storage tank precooling apparatus, including tank wagon interface, precooling pipe, vaporizer, controller and storage tank interface, wherein, tank wagon interface, vaporizer and storage tank interface pass through precooling pipe serial connectivity, be provided with automatic control valve group on the precooling pipe, controller and the automatic control valve signal connection of group for the switching of control automatic control valve group.