In this work, an environmental friendly dust suppressant with improved wettability and coagulation properties was developed by a chemical modification method. The hydroxypropyl guar gum was synthesized by nucleophilic substitution reaction between natural polymer guar gum and propylene oxide. Through a series of optimization of adjuvant agents and viscosity experiments, the optimum formulation contained moisture agent W + 0.8% hydroxypropyl guar gum. A mastersizer 3000 laser particle size analyzer was used to determine that the wettability of coal dust increases with the increase of particle size. The dust suppression agent and coal dust were fully mixed and bonded together, as observed by a high-resolution scanning electron microscopy. The spray dust reduction experiment results show that the spray dust reducer developed in this paper can significantly reduce the dust concentration, and the average dust removal rates of total dust and respirable dust are increased to 83.94% and 84.08%, respectively. (C) 2019 Elsevier B.V. All rights reserved.