Abstract: In order to solve the less advantage of existing mobile liquid carbon dioxide fire extinguishing device in some aspects such as overall technical performance index, adaptability to harsh environments, easy to operate, and technical measures of the ice blocking, liquid heat preservation, safety assurance and so on, a new kind of underground emergency rescue equipment used in fire extinguishing is developed. Sealing vacuum degree of the storage tank is 1.6 Pa, which is better than the national standard value (3.0 Pa). After performance test of the heat preservation, the overall and actual daily evaporation rate is about 0.09%, which is the standard value of 30%, it can reduce the infiltration of external heat effectively, extend the time of heat preservation.