Abstract: In order to prevent and control the leakage risk and explosion accident of pulverized coal in the pulverized coal preparation system, a test system for the occurrence of water mist was set up. The characteristic parameters such as atomization angle, flow rate and particle size of a solid conical nozzle were tested under different working pressures.The experimental results show that with the increase of spray pressure, the water flow rate increases linearly and the particle size decreases gradually; when the pressure is 2.0 MPa, the water flow is dispersed into fine water mist with small particle size, the flow rate is 19.62 L/min, and the median particle size of fine water mist is 146.3 μm. Based on the dust removal and explosion suppression mechanism of fine water mist, the dust suppression and explosion suppression system is designed. The water mist supply flow rate and the number of spray nozzle in different areas of pulverized coal preparation system are designed and calculated, the arrangement of spray nozzle are studied, which provide reliable guarantee for the safe operation of pulverized coal preparation system.