Forewarning of rock burst is an important technical method to ensure the production safety of working face. It is of practical significance to analyze and study the forewarning index and quantify the relevant parameters. In order to study the stability of coal and rock mass and the law of energy impact release under the condition of extra-thick coal seam, microseism monitoring technology was used to evaluate the effect of roof cutting and pressure relief in Tangjiahui Coal Mine, and an forewarning index of rock burst prevention and control based on microseism energy was established. The research results showed that the forewarning index based on microseism monitoring technology could play a good role in the advance warning of local pressure and periodic pressure in the working face. The forewarning index and technical method could provide a way of idea and method for the evaluation of the effect of roof cutting and pressure relief and the fine management of the forewarning index of rock burst prevention and control in coal mines.