Abstract: In order to prevent and reduce the harm caused by the lithium battery fire of electric vehicles, this paper analyzes the current situation of the fire in electric vehicles, investigates the cases of the fire in electric vehicles in recent years, and conducts the heating test for the single cell and the cell in the middle of the battery module in the power lithium battery according to the structure of the cell and the power lithium battery group. The results show that the power lithium battery will not explode violently, but it has the characteristics of violent fire and rapid spread. Based on the analysis of the thermal runaway mechanism and fire process of the power lithium battery system, the fire extinguishing technology of the power lithium battery fire of electric vehicle is studied, and the fire extinguishing technology and method suggestions are put forward in combination with the actual work.

Key words: electric vehicle, lithium battery, combustion; thermal runaway, fire fighting technology