Abstract: In order to improve the working environment of fully mechanized mining face, reduce the concentration of falling coal dust after cutting by shears, and improve the safety management level of coal cutting operations, this paper studies the method of mechanical cavitation in coal wall construction boreholes to achieve crack reflection enhancement, so as to improve the effect of coal body water injection. The compressive strength and seepage effect of coal wall as well as the change of surface tension after water injection are studied. By analyzing related parameters such as the degree of pore fissure development and the diameter of flow channel, the design scheme of borehole reaming and water injection parameters was determined. Through experimental demonstration, it was found that the water content of coal after cavitation was increased by 57.8% compared with that of ordinary borehole water injection. The dust concentration of the upper end, the return air flow 10 ~ 15 m area, 25 ~ 30 m area and other different places were measured, and the measurement results were reduced by 72.5%, 68.1% and 46.3%, respectively, which has a significant dust reduction effect.