Abstract: To improve dust explosion test method,a testing system is established based on 20 L spherical explosion test spparatus to test coal dust explosion parameters. Compared with the chemical ignition,the discharge time of electrostatic ignition is short.For laboratory experiment,electrostatic ignition is both safe and reliable.The experiment adopts electrostatic ignition to study explosion properties of different sizes of coal dust.The experiment has measured the coal dust explosion parameters under different conditions.The results show that with the increase of coal dust concentration, explosion pressure, maximum rate of pressure rising and other explosion parameters first increase and then decrease.The particle size influences explosion characteristics greatly. The smaller the coal dust particle size,the more violent the explosion. With the increase of ignition energy, explosion pressure and the maximum rate of pressure rise increase gradually. When the ignition energy increases to a certain value, these parameters tend to be stable.