The utility model discloses a water cyclic utilization's automatic spray dust fall cooling system belongs to construction technical field, solves the problem that current building site manual controlspray dust -fall is untimely, the effect poor and waste water, collect circulation system and automatic spraying system including water, water is collected circulation system and is included tertiaryfilter tank and lead, and automatic spraying system includes monitoring device and spray set, and monitoring device includes soot sensor, and soot sensor evenly distributed is around foundation ditchor building subject, spray set includes water pump, main conduit, electrical control valve and atomizer, and tertiary filter tank is connected to the water pump, and the main conduit is connected to the output of water pump, and the atomizer is connected to the main conduit, is provided with electrical control valve on the main conduit, soot sensor electric connection electrical control valve andwater pump, electrical control valve electric connection water pump. The utility model discloses make full use of rainwater and construction and domestic sewage to the cooling of automatic spray dustfall, it is effectual, the water economy resource.