Abstract: Aim to effectively reduce the harm caused by high concentration coal dust to the health of underground workers, and mine tap water has lower wettability and viscosity, a composite dust depressor composed of surfactant, synergistic ion and cellulose are developed through sedimentation experiments and viscosity test experiments and orthogonal design method.The experiment shows that after adding the composite dust depressor, the coal dust settling time is only 4.1 s, the viscosity is 24 times of the tap water for mining, and the wettability and viscosity are significantly stronger than the common dust suppressant.The field application results show that after adding the composite dust depressor to the internal and external spray of the roadheader, the average dust control efficiency of the whole dust and the dust is 95.0% and 92.8%, respectively.Compared with the total dust before the composite dust suppressant, the dust control efficiency increased by 25.0% and 29.1%, respectively.