The study of natural fire rule and prediction technology in Hanglaiwan Mine of Yulin Coal Industry showed that coal seam No. 3 had the risk of natural fire and was a "Type I" coal seam prone to spontaneous combustion. Through the study of the technical conditions of the No.3 coal seam, the technical solution of grouting and fire prevention was explored, the selection of grouting method, grouting material and grouting parameters were summarized, and the precautions in the implementation of grouting and fire prevention technology was pointed out. Since the implementation of grouting fire prevention and suppression technology in this coal seam, the risk caused by natural fire was effectively reduced, and the coal mine fire prevention was safe and controllable.