Abstract: In order to solve the problem of water hazard caused by Ordovician limestone in coal seam mining in deep areas, this paper takes the exploration and control project of multiple working faces at the -980 m level in Xingdong Coal Mine as an example, through the analysis of the geological and hydrogeological conditions of the mine and the working face, the main water filling source, water filling channel and exploration and treatment layers during the mining of the working face are determined. Combined with drilling exploration and grouting control project, the effective prevention and control of Ordovician limestone water hazard in the study area has been completed through the tests of engineering effect. The results show that, the main water-filling threat during mining in the study area comes from the water in karst fissure aquifers of Ordovician limestone in coal floor, and the main water-filling channel is fault tectonic zone. Through drilling engineering exploration, 1 surface main hole and 40 underground near horizontal branch holes were constructed. According to drilling effect tests such as gamma logging, water level observation and water temperature observation, it was determined that this exploration detected 1 concealed collapse column （X8）and individual water-conducting fault structures such as No.F₂₃ fault. After grouting engineering treatment, it is considered that the development degree of Ordovician limestone karst fissure in coal seam floor is uneven, the correlation between grouting amount and multiple indexes is poor, and the grouting condition is relatively complex. The grouting effect is good after the final pressure, unit water absorption rate and the actual situation. Through this Ordovician limestone water hazard exploration and control project, the safety production in the deep mining area is ensured.