The invention discloses a dust control unit for road construction, which comprises a car body, a water tank, a water pump, a supporting pillar, a spray cylinder, a cross plate, a water pipe, a connecting rod, an installing plate, a high-pressure nozzle, a first motor, a flexible pillar, a roll bead, a top plate, a rotating shaft, a second motor, a side plate, a damping spring, a buckle, a hydraulic pillar, a bolt rod and a bearing. The invention has the beneficial effects that the bottom part of the spray cylinder is connected with the side plate through the rotating shaft, and the bottom partof the top plate is connected with the motor, thus the spray cylinder can spray water mist to the outer part in working, impurities and dust in the air can be fallen and removed by the effect of thewater mist. During the working process of the spray cylinder, the first motor drives the top plate to rotate on the horizontal direction from the bottom part, the second motor drives the rotating shaft and the spray cylinder to rotate on the vertical direction; two motors are cooperated so that the spraying cylinder can change the dust removing direction on the vertical direction and change the dust removing direction on the horizontal direction during the working process.