Abstract: Hydroxypropyl starch is used as the main raw material,N,N-methylene-bis-arcylamide as a cross-linking agent,ammonium persulphate as an intiator,sodium carboxy ethyl cellulose as a viscosity regulator and film-forming agent,a coal dust-depressor with fine moisture,anti-rheumatic,water stability and temperature resistance is gotten.By comparison,the technology indicators of this suppressant are well than pure starch-based coal dust-depressor in some aspects such as anti-rheumatic,water stability and temperature resistance.Cross-linking reaction could form a network structure,and improve product's moisture and the resistance to wind erosion,but it could also reduce product's viscosity,is not conductive to film-forming property,so controlling the degree of cross-linking is critical.Optimum reaction conditions are a temperature of about 70 degrees,and time of 1h.