Abstract: the threat of roof bed separation water disaster to coal production is increasing day by day, and it has become a research hotspot of mine water disaster prevention and control in recent years. Systematically summarizes the research progress of roof bed separation water disaster at home and abroad, and expounds the problem of coal bed separation water disaster from four aspects: formation mechanism, disaster-causing mechanism, prediction and early warning and key prevention and control technologies. Summarizes the research on mining overlying bed separation and the formation mechanism of bed separation water, and summarizes the formation of the bed separation water into three basic conditions: the bed separation which can accumulate water, the existence of recharge water around the separation, and the separation space lasting long enough. According to the mining conditions, the engineering geological conditions of the overburden rock, water channel formation reasons and water inrush characteristics, expounds the disaster-causing mechanism of the bed separation water disaster from four aspects: repeated disturbance water inrush under multi-coal seam superimposed mining, dynamic water inrush under multi-coal seam superimposed mining, hydrostatic water inrush effluent under single coal seam mining and formation mechanism of bed-separation water disaster in Jurassic coal field. Mainly analyze Three typical formation mechanisms of bed separation water inrush in Jurassic coalfields: the formation mechanism of Cuimu and Zhaoxian high bed separation water inrush, the formation mechanism of New Shanghai No.1 intermittent bed separation water inrush, and the mud-carrying sand type bed-separation water inrush. According to the energy source and performance characteristics, the bed separation water inrush can divide into three categories: dynamic water inrush, hydrostatic water inrush and underground debris flow with sand and mud from bed separation. Summarizes the research progress of bed separation water disaster prediction from three aspects: the prediction of the position of water separation, the periodic prediction of bed separation water inrush and the prediction of bed separation water inrush. Analyzes and introduces the main prevention and control methods of bed separation water disaster, and analyzes the difficulties of the prevention and control of bed separation water disaster in Jurassic coalfields of Ordos Basin: the strong ore pressure caused by water inrushing at high bed separation level and the sand collapse caused by water inrushing at high bed separation level. Propose the future development and research direction of bed-separation water damage prevention and control: to carry out the research on the accurate prediction and zoning of separated layer water disaster before mining; to develop the exploration technologies such as drilling and geophysical exploration to change the overburden damage from "gray box" to "white box"; to develop the comprehensive prevention and control technology system of separated layer water disaster.