Abstract: Based on the experimental study of gas desorption laws of different damage level,different metamorphic grade,different pressures,different temperatures and different moisture of tectonic coal,concluded the laws that the total gas-desorption volume of unit tectonically coal is increased with increasing of damage level,temperature and pressure,and it is decreased with the increasing of metamorphic grade,moisture in coal,this research result provided a theoretical basis for the prevention and treatment of gas disaster of coal mine.