Abstract Water inrush through coal floor is a common hazard in the coal mining process of coal fields in northern China. Monitoring and early warning of water inrushes is a new topic of the disaster prevention and reduction work. Some basic questions, concerning the monitoring conditions, the monitoring and early warning index and technology system, and the selection basis for monitoring points and layers were discussed. An early warning criterion system which includes stress, water temperature and water pressure was established. The rationality of the monitoring and early warning technique was verified preliminarily by an engineering practice which was applied on the 2113 coal face in Chengjiao coal mine. This study can be referenced by further study to monitor and provide early warning of water inrushes through coal floors.