Abstract: In order to control the large amount of coal dust generated during coal washing and transportation processes, a new-type dust suppressant is developed with porous structured sepiolite as skeletal material and grafted and copolymerized corn straw with acrylic acid, using emulsion polymerization method. The process conditions are optimized, and the effect of the suppressor is characterized. Test results indicate an optimal process conditions can be achieved at a sepiolite-corn straw ratio of 1.5, a dosage of initiator of 10～15 mL, a dosage of cross linking agent between 1 g and 2 g, a dosage of acrylic acid of 90～100 mL, and a polymerization temperature of 45 °C; when the gelatinization temperature maintains at 90 °C for 30 minutes with the polymerization temperature keeping at 45 °C for 2 hours, the prepared dust suppressant exhibits a high water absorption capacity; when the diluted, dust suppressant is directly sprayed onto the surface of a coal pile, a relatively flat and firm film can be formed; the higher the content of acrylic acid, the shorter the film forming time and the firmer the texture of the formed film; the suppressant demonstrates remarkably high evaporation-resistant and long-term water retaining capacities demonstrated by results of tests on physiochemical property and effects of the suppressant, the suppressant proves to be an efficient chemical coal dust suppression material. When directly and repeatedly sprayed onto the surface of the coal pile, a satisfactory dust suppression effect can be obtained with an effective time of more than 7 days without causing secondary environmental pollution. The research results have a broad application prospects for coal dust control.