Abstract: A separate water-stop device installed in the hole was developed, in order to solve the problems of large depth, small number of surface hydrological monitoring holes and relatively insufficient density of monitoring points in the eastern mining area in China. , Corresponding hole-forming and well-flushing technical requirements and installation were proposed. The operation process formed a set of double-layer monitoring technology and equipment suitable for long-term groundwater monitoring of coal mines. The research results effectively improved the utilization of ground monitoring holes and increased the density of monitoring points. The researched separate water-stop equipment is simple to produce, suitable to various hole formations, and is easy to install and operate. It can be installed in both new geological exploration holes and hydrogeological exploration holes, and can be installed in the original mixed-layer monitoring holes, with a little transformation into double-layer monitoring holes. The technology and equipment have been verified in the ground monitoring hole of a mine in Shandong Province. The monitoring results show that there is a significant difference in the monitored water levels of the upper and lower aquifers of the double-layer monitoring hole, the water level trend is completely different, and there is no cross layer phenomenon between the upper and lower layers. The purpose of double monitoring of one well is successfully realized. The equipment has the advantages of simple processing, low hole forming requirements and simple installation and operation. It is suitable for installation in all kinds of boreholes in coal mine area and has high practical value.