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With complicated geological conditions,coal mines are under bad threat of gas disasters in China,especially in the southwest.However,its hard to control such disasters,which greatly restrict the safe and efficient production of coal mines,by using traditional technologies.A new idea is proposed to solve this problem using water jet to prevent and control gas disasters by making fractures in the coal seam to pre-drain gas combined with advanced disaster prevention technology.By investigating the mechanism of breaking coal-rock and strengthening methane desorption using multi-phase oscillating water jet,a new technology of gridding fracture-making to improve the permeability of coal seams is proposed.The new process and whole-set equipment of advanced gas pre-drainage are developed and a new system of three-dimensional gas pre-drainage before coal mining is also built.The new technology has been used to establish gas-control demonstration project in the southwest and then popularized and applied nationwide.The application effect shows that this new technology greatly raises the permeability coefficient by more than 1000 times,shortens the preparation cycle before coal mining from 2-4 years to 1 year,lowers the gas control cost for per ton coal by 50%,brings the utilization ratio of CBM up to 80%,and realizes the prevention and control of gas disasters in complex coal seam as well as the exploitation and utilization of CBM.