Abstract: In order to solve the problems of high surface tension, poor wetting properties and low spray dust rate of dustproof water, based on the analysis of the dust reduction mechanism, combined with the surface tension, contact angle and water retention experiment of dust-depressor, the dust-depressor agent was developed that we call it complex reagent B with efficient and environmental characteristics. The research showed that after using the reagent B, the surface tension reduced by 61.73%, the contact angle reduced by 53.66%, and the water retaining rate was 3 times of the original state. The application results of a coal mine showed that the dust-laying rate was above 80% after adding dust-depressor, compared with the clear water spary, the dust-laying rate increased by more than 20% on average, and the effect of dust-depressor is more obvious on respirable dust.