The invention discloses a roadway-mining face collaborative water injection structure for dust fall of coal mine. Water injection drill holes are formed in the sides, close to a coal seam, of an air inlet roadway and an air return roadway, the drill holes are single-row holes, the hole opening positions are located in the center line of a coal wall, the hole opening direction is along the dip angle of the coal seam, the horizontal angle is 0 degree, water injection pipes are installed in the drill holes, and hole sealing water injectors are fixed to the water injection pipes. The water injection method comprises the following steps that 1, roadway and mining face drilling construction and timely water injection are carried out, and the hole depth and the dip angle are adjusted according to the field condition; 2, a water injection hole is subjected to hole sealing treatment; and 3, a water injection main pipeline flowmeter is installed on site, and water is injected into the water injection holes through the water injector according to a water injection scheme. The method can effectively wet the coal body, reduce the dust yield of the mining face, improve the water injection efficiency of the coal seam, and inhibit the generation of dust from the dust production source.