Abstract: In the process of mining activities in coal mining face, the existence of aquifer on the top and bottom often poses a serious threat to the quality management and safety production of roadway engineering. In order to take effective measures to fill and plug the water-conducting cracks, polyurethane was selected as the grouting material, and the physical properties of the improved polyurethane material were investigated by adding under laboratory conditions. The basic physical properties such as density, viscosity, expansion rate, foaming rate and compressive strength of the improved grouting material were improved. After practice verification in the 1905 working face, through the comparison of water inflow before and after grouting, it was found that the water inflow in 4 places decreased by 65.2% and 80.4%, 77.8% and 76.4%, respectively, and achieved significant water control and leakage plugging effect.