Abstract: A “well-ground” combined microseismic monitoring system is designed, and the principle of microseismic positioning and epicenter scanning algorithm are discussed.The hardware scheme for the system is designed, and clock synchronization technology based on GPS timing principle was adopted to achieve the synchronous data collection of underground and surface substations.Microseismic monitoring stations in the underground working face and on the overlying surface are set up for on-site application, and the monitoring data shows that the system can effectively identify and locate microseismic events generated by underground mining activities, accurately determine whether there is any situation of cross-border mining, and provide effective technical means for coal mining exploration and cross-border mining monitoring.