The invention provides a lithium-ion battery module thermal runaway automatic cool and cooling system for a new energy vehicle and its realization method and relates to a battery cooling and cooling system, in particular to a lithium-ion battery module thermal runaway automatic cooling and cooling system for new energy vehicles. Includes a liquid circulation cooling part, a temperature monitoringpart, a control part and an auxiliary device part; A temperature monitor section and a liquid circulation cooling section are connected with that control section, respectively. The invention has the advantages of automatic control, simple operation, good cooling effect and the like. When the temperature of the lithium battery rises, the temperature can be judged, and the lithium-ion battery moduleof the new energy vehicle is cooled by three stages, so as to avoid the lithium-ion battery module from losing heat control and forming domino effect due to the continuous rise of the temperature ofthe lithium-ion battery module itself, thus causing huge casualties and property losses of the lithium-ion battery module.