The Huanglan coal mining area is the most threatened mining area in Hunan Province by water hazards, which seriously affects the sustainable development of the local coal industry. Accurate detection of hidden water hazards can effectively reduce the probability of hidden dangers, and exploring more efficient technical methods and using high-precision detection instruments are effective ways to solve this problem. Multi-polarized magnetotelluric technology (MPMT) measures electric field polarization at different polar distances at a common center point to obtain Kania resistivity at different polar distances, thereby obtaining more dimensional electric field data, local anomalies, and background data, which can more efficiently meet the needs of geological body detection in complex geological environments. According to the hydrogeological conditions of the Huanglan mining area, the multi-polarized magnetotelluric method was used to carry out work, analyze its application effect and electrical properties of the mining area, and prove the effectiveness of the method through known water body experiments and apply it to the whole area of water hazard exploration. The comparison between the interpretation results and the actual excavation conditions of later tunnels proves the accuracy of the method, providing a scientific basis for the design of drainage tunnels, drainage measures, and safety prevention of groundwater in the Huanglan mining area.