Abstract: Abstract: In order to study the protective effect of high pressure water mist on cable fire in equipment room of rail transit hub station, a full?scale test model of equipment room of rail transit hub station was established by using the method of entity experiment, and the fire extinguishing mechanism, main design parameters and system selection were expounded. The results show that the pre?acting high?pressure water mist can effectively restrain the cable fire combustion and prevent the cable fire from spreading in the horizontal direction. After the application of fine water mist for a period of time, the ambient temperature of the test was restored to about 25 ℃, and the change range of oxygen volume fraction after the application of fine water mist was small, the lowest was 20.62%, which would not cause harm to human body. Pre?acting water mist system can reduce water damage.

Key words: urban rail transit hub station, room for equipment, pre?acting system, water mist, cable fire