Fire-fighting smoke exhaust air pipe

The fire-fighting smoke exhaust air pipe comprises a pipe body, a concentric-square-shaped scraping plate is arranged in the pipe body in a sliding mode, a blowing plate is fixed in the concentric-square-shaped scraping plate, a reset assembly for driving the concentric-square-shaped scraping plate to move is arranged in the pipe body, a shovel plate for pushing smoke dust is fixed to one side of the concentric-square-shaped scraping plate, and a discharging opening for discharging the smoke dust is formed in the bottom end of the pipe body. A collecting box located below the discharging opening is arranged at the bottom end of the pipe body. According to the fire-fighting smoke exhaust air pipe, when the pipe body exhausts smoke, the blowing plate is driven to move under the airflow effect of the smoke, the blowing plate drives the concentric-square-shaped scraping plate to move, smoke particles attached to the inner wall of the pipe body can be scraped and cleaned through the concentric-square-shaped scrapi