The utility model discloses a circulating water dust collector for construction of highway, including casing, sprinkler, sewage case, clarifier, fender stream board and storage water tank, sewage caseand storage water tank all are located the casing and pass through clarifier interconnect, sprinkler is located sewage case top and tank connection, it is higher than location of sprinkler head at casing upper surface and top edge to keep off stream board slope setting, keep off and flow board lower extreme edge connection to sewage case, the casing comprises last top surface and body lock, the clarifier comprises motor, inlet tube, a purifying core pipe, the 2nd purifying core pipe, connecting pipe and outlet pipe, sprinkler comprises shower nozzle and spray pipe, spout head position in sewage case top and through spouting water piping connection to storage water tank, the shower nozzle is in to the air and circularly sprays in the storage water tank uncontaminated water and make the hydrone atomizing for dust gathering in the air receives gravity to fall into the sewage case on little water droplet, sewage that the sewage case was collected gets into the storage water tank after passing through purifier purification, storage water tank rethread spray pipe with meet and discuss to spraying uncontaminated water in the air, reach the effect that water resource recycle utilized, avoid sewage directly to flow to ground.