Automatic dust falling device

The invention provides an automatic dust falling device, which relates to building construction and comprises two symmetrically arranged spraying rods, a base fixedly mounted at the bottoms of the spraying rods, a plastic water pipe communicated with the spraying rods, an air bag arranged between the two spraying rods and air pipes communicated with the two sides of the air bag, the spraying rod comprises an upper spraying head, a lower spraying head, a steel water pipe, a pneumatic self-closing damping water valve and a pipeline connecting piece. According to the spraying device, 'advanced starting and delayed closing 'of spraying can be achieved, that is, spraying is started in advance before the muck vehicle passes through the spraying device, the road surface and air are wetted, dust raising is reduced, spraying can still be continued for a period of time after the vehicle passes through the spraying device, and it is ensured that dust raised behind the vehicle can settle down. 本申请提供了一种自动化降尘装置，涉及建筑施工，包括两个