Abstract: Influence of particle size, concentration and ignition energy of coal dust on the maximum pressure and its rising rate of coal dust explosion were researched by use of 20 L spherical explosion equipment. The research results show that under the condition of certain particle size of coal dust, the maximum pressure and its rising rate of coal dust explosion will increase firstly and then decrease along with increasing of concentration of coal dust. When concentration of coal dust is in 400-480 g/m3, the maximum pressure and its rising rate of coal dust explosion achieve the maximal value of 0.94 MPa and maximum 28.79 MPa/s respectively. Under the condition of certain concentration of coal dust, the maximum pressure of coal dust explosion will not change in a similar tendency and its rising rate will increase along monotone with decreasing of particle size of coal dust. The maximum pressure and its rising rate of coal dust explosion will increase significantly along with increasing of ignition energy.