Ventilation device for building construction

The utility model relates to the technical field of ventilation equipment, and discloses a ventilation device for building construction, which comprises a barrel body, a fan and a filter cartridge, two rotating pins are rotatably arranged on the inner wall of the barrel body, one ends of the two rotating pins close to each other are fixedly provided with a same mounting rack, the fan is fixedly arranged on the mounting rack, and the filter cartridge is fixedly arranged on the barrel body. Two clamping plates are slidably mounted on the barrel, the same two-way lead screw is mounted on the two clamping plates in a threaded mode, a rotating shaft is rotatably mounted on the inner wall of the barrel, the rotating shaft and the two-way lead screw are fixedly sleeved with a driving bevel gear and a driven bevel gear respectively, and the driving bevel gear is meshed with the driven bevel gear. And the front end of the rotating shaft extends out of the barrel and is fixedly sleeved with a hand wheel. The fan has th