Abstract: In order to solve the difficult problem of high dust concentration and high respiratory dust hazards in fully mechanized excavation working faces of coal mines, optimization and research of nozzle layout for mineral gas water mist dust reduction system is carried out. Taking the 3101 fully mechanized excavation working face of No.3 coal seam in Sima Coal Industry Co., Ltd. of Lu'an Chemical Group as the background, the spatiotemporal distribution law of dust in the excavation working face is revealed through a combination way of on-site actual measurement and numerical simulation, and the existence of downstream respiratory dust enrichment areas is pointed out. Based on the atomization characteristics experiments of air-water nozzle, the optimal working condition parameters are determined. On this basis, combined with surfactant modified fog droplets to improve the wetting efficiency of hydrophobic coal dust, a zoning collaborative three-dimensional dust reduction nozzle layout optimization scheme of "source suppression+midway interception" is proposed. The industrial test results show that, compared with the dust reduction efficiency of 45.3% of the total dust and 33.1% of the respiratory dust of the conventional spray system before optimization, the dust reduction efficiency of the optimized scheme for the total dust and respiratory dust is improved to 91.0% and 88.0% respectively, which effectively improves the operation environment.