The invention discloses a road and bridge construction spraying dust fall device which comprises a bottom plate, a handrail is fixedly arranged at one end of the bottom plate, fixing blocks are fixedly arranged at the four corners of the bottom of the bottom plate, connecting shafts are rotatably inserted into the fixing blocks, rolling wheels are symmetrically and fixedly arranged at the two ends of the connecting shafts, and a mounting rod is rotatably inserted into the top of the end, away from the handrail, of the bottom plate. A connecting mechanism is fixedly arranged between the mounting rod and one of the connecting shafts, a dust collection mechanism is fixedly arranged at the bottom end of the mounting rod, rotating rods are symmetrically and rotationally inserted into the two sides of the top end of the mounting rod, limiting mechanisms are fixedly arranged on the rotating rods, and a supporting plate is fixedly arranged at the ends, away from the mounting rod, of the rotating rods; a fixing base is fixedly arranged at the end, away from the rotating rod, of the supporting plate, and a fixing mechanism is fixedly arranged at the top of the fixing base. According to the spraying and dust falling device for road and bridge construction, dust on the ground and water drops adsorbing the dust can be cleaned while spraying and dust falling are carried out, rotating spraying and dust suction are carried out in the moving process through the connecting mechanism, and the efficiency is improved.