Abstract: In recent years, the safety situation in the country is severe, and with the transformation of energy structure in our country, UHV projects have entered a new stage of large-scale construction. The UHV projects distributed in the frigid and high altitude areas face complex and severe production risks, especially fire risks because of drought and water shortage in the high altitude areas. In view of the problems such as the inability of on-site emergency resources to be deployed in time when a fire occurs and the inability of existing on-site emergency resources to meet the needs of emergency treatment, this paper developed a mobile compressed air foam fire extinguishing device for small initial fires, applied it to 1000 kV UHV substation in Ganzi, and carried out on-site emergency drills. The fire extinguishing effect of the high mobility compressed air foam extinguishing device is verified.