Abstract: Taking the +425 m horizontal working face of B3-6 coal seam in Wudong Coal Mine as the engineering background，combined with indoor coal moisture content mechanics test，numerical simu⁃ lation and on-site microseismic monitoring methods，coal seam water injection on pressure relief and rock burst prevention is systematically studied. The results show that the main stress concentration areas are the upper and lower parts of the roadway，the end of the working face and the lower part of the goaf after the mining of the near-vertical coal seam. When the pressure relief measures are not taken，the maximum hori⁃ zontal stress peak of the roadway is 35 MPa，and the vertical stress peak is 20 MPa，and the impact risk is high. After the implementation of coal seam water injection，the mechanical properties of coal body are weakened，the stress of surrounding rock is effectively released，the peak value of vertical stress is re⁃ duced by 5 MPa，the stress concentration coefficient is significantly reduced，and the shallow concentrat⁃ ed stress is transferred to the deep part of coal body. Field monitoring shows that coal seam water injection can increase the frequency of microseismic events，reduce vibration energy，reduce high-level vibration events，and achieve progressive release of elastic energy of coal and rock mass. The study confirmed that the coal seam water injection can effectively weaken the stress concentration of the surrounding rock of the nearvertical extra-thick coal seam，optimize the energy release law，and significantly reduce the risk of rock burst，which can provide reference for the prevention and control of rock burst disasters in similar mines.

Key words: near vertical extra-thick coal seam, coal seam water injection, rock burst, numerical sim? ulation, microseismic monitoring