Abstract: In view of the problem of low dust removal efficiency by water spray and based on the analysis of the dust removal process by water spray, four important technical parameters that influences the dust removal efficiency by water spray were obtained, including the flow of water spray, spray particle size, spray range and the covered area of spray. Through modeling analysis, theoretical research and the summary of practical experiences, the calculation expression or optimal matching range of the four parameters. Four parameters were applied for the optimization of the spraying dust-removal system in 20106 fully mechanized caving face in Wangjialing Mine, and the application results showed that the dust removal efficiency respectively reached 97.18% and 96.08% at the driver position and 10 m place on the downwind side.