Abstract: Based on the good properties of plugging, cooling, resistance, consolidation of water for colloidal mud material, it is injected into the fire zone with the borehole pressure injection mode. Using the property of wrapped coal after gelling of the material, it can effectively overcome the loss and leakage of water of traditional grouting and water injection. Practice has proved that new colloid slurry material has a good fire prevention performance; It does not rapidly vaporized in flame near 1 000 ℃ and In the underground environment humidity of 90 %, temperature of 28 ℃ condition, fire prevention performance can keep for more than 13 months.