With the deep mining of North China-type coalfield, the threat of mixed water source is increasingly serious, and water inrush accidents occur from time to time. Identifying the water inrush dynamic of limestone-mixed water source in high geothermal coal mine is difficult. This paper constructs a radioisotope distribution model of deep groundwater and obtains the dynamic data of radium and radon on the basis of the decay law of radionuclides and the principle of water balance and mass conservation. The radium–radon dating model is used to obtain the age of groundwater. Combined with the data of uranium and temperature, a dynamic identification model of multilayer limestone-mixed water source in coal seam floor is established by using a multielement mixed mass balance calculation method (M3). The relationship between the age of mixed water source and the mixing proportion of temperature and the contribution of recharge end member can be interpreted. The age of deep groundwater is negative correlation to the temperature. The temporal and spatial changes in mixed water sources and the response mechanism of radium–radon are described. Research results provide a new method to identify the source of water gushing in high geothermal coal mine, which is of great importance to improve coal mine safety production.

随着华北型煤田的深采，混合水源威胁日益严重，突水事故时有发生。高地热煤矿石灰石混合水源突水动态识别难度较大。本文根据放射性核素衰变规律和水平衡质量守恒原理，构建了深层地下水放射性同位素分布模型，获得了镭和氡的动态数据。镭——氡定年模型用于获取地下水年龄。结合铀和温度数据，采用多元素混合质量平衡计算方法（M3）建立煤层底板多层石灰石混合水源动态识别模型。可以解释混合水源年龄与温度混合比例和补给端元贡献之间的关系。深层地下水年龄与温度呈负相关。描述了混合水源的时空变化和镭-氡的响应机制。研究成果为高地热煤矿涌水源的识别提供了一种新方法，对提高煤矿安全生产具有重要意义。