When the device is in a normal state,if the pressure level in the tank drops,control cabinets start fill pumps to the tank fill water up to the set value if the system pressure drops below a set value,control cabinet starts to fill the tanks of air compressor gas to air-water equilibrium.After receiving the fire signal,control cabinet control low pressure solenoid valve on the bottle to start,low pressure gas-driven high pressure bottle bottle bottle combination valve is opened,high pressure gas through pressure relief devices relief backward into the pressure tank to the gas appliance water goes into fire-fighting water system.After completely goes against the effective volume of water,low liquid level switch control air solenoid valves,cut off the connection of equipment and fire-fighting water system to prevent gas entering the system