• In-depth study of coal dust wetting mechanism. • Application of molecular dynamics simulation in dust suppressants. • Study on the mechanism of dust suppression by combining different surfactants. To further improve the effect of dust control in coal mines and protect the health of workers, the effect of sodium alginate (SA) on the dust suppression ability of sodium methyl ester sulfonate (MES) was studied using molecular dynamics simulation. Scanning electron microscopy and X-ray photoelectron spectroscopy analyses were performed to compare the dust suppression effect of the SA/MES dust suppressant compound to MES by itself. The results show that when SA is present, the coal dust bonds together more, agglomerates into large particles, and settles. This finding is also consistent with the results of molecular dynamics simulations. In the analysis of relative concentrations and mean square displacement, the presence of SA can reduce the water diffusion on the coal surface, making it easier for coal dust to agglomerate. In addition, we analyzed the mode of action of SA through radial distribution and electrostatic potential, and determined that SA forms a unique networking chain structure to capture and retain water molecules. SA increases the probability of interaction between water and surfactant, thus increasing the amount of adsorption. This study provides a more in-depth understanding of the dust suppression mechanism of mixed dust suppressants.