Abstract: By using HCA high pressure capacity gas adsorption device, the gas adsorption capacity and gas adsorption constant of 7 groups of coal samples with different degree of metamorphism were tested in the temperature of 20 ℃, 30 ℃, 40 ℃, 50 ℃, 60 ℃ respectively.Through the analysis and study of the test data, the relationship model between the decrease of gas adsorption and the degree of metamorphism of coal for every increase in temperature was obtained, and then the formula for calculating the gas content in coal seam by indirect method was calibrated. The correction result was more consistent with the theory that the adsorption saturation of coal sample was imminent at high pressure.