Fire-fighting smoke exhaust fan

The utility model discloses a fire-fighting smoke exhaust fan which comprises a fan barrel, and an air inlet and an air outlet are formed in the fan barrel. The smoke exhaust fan blades are arranged in the ventilating duct and are close to the air inlet; the smoke exhaust fan blade driving mechanism is erected in the fan barrel; the smoke exhaust fan blades are in transmission connection with theoutput end of the smoke exhaust fan blade driving mechanism; a dust falling system is arranged at the end, close to the air outlet, in the fan barrel. A first water supply port and a second water supply port are further formed in the fan barrel; a water inlet A of the water cannon is connected with a first water supply port in the fan barrel through a first fire hose; a water inlet B of the dust falling system is connected with a second water supply port in the fan barrel through a second fire hose; the axis of the fan blade rotating shaft and the axis of the water cannon water outlet A are parallel and located on the