Abstract: The 6th coal seam floor of Tangjiahui Coal Mine is seriously threatened by Ordovician karst water. It is the mine with the deepest mining depth and the highest water pressure in Zhungeer Coal Field. In order to eliminate the threat of water damage from Ordovician floor, the ground area treatment test project was carried out on the 61207 working face of Tangjiahui Mine. The test results show that there are many leakage and return phenomena during the directional drilling process, the grout is large in the grouting project, the efficiency of drilling and grouting is low, and the 61207 working face adopts the ground area treatment method to prevent and control the floor Ordovician water damage. The construction period is long, and it is difficult to meet the needs of continuous cost control of the face production. Through comprehensive comparative analysis, it is advisable to adopt the technical route of water prevention and control, which is the combination of “bottom exploration and reinforcement by directional drilling inside working face” and “treatment of fault zone by directional drilling outside working face”.