Abstract: In order to realize the recycling use of the ventilation air methane(VAM) at the upper corner angle of the coal mine, the nitrate, ammonia and sodium hydroxide were respectively used for the modification of the coconut shell activated carbon. The modified activated carbon was then used for the vacuum pressure swing adsorption(VPSA) of the low-concentration gas, and on this basis, study was carried out on the structural change of different modified activated carbons and their absorption capacity to the methane. The study results showed that the absorption capacities of the activated carbons modified by the nitrate, ammonia and sodium hydroxide to the mine ventilation air methane were all improved to a certain degree. It was found from the comparative experiments that the activated carbon modified by sodium hydroxide had the best adsorption ability to the methane, when the concentration of sodium hydroxide was 2 mol/L and the dipping temperature was 60℃, its adsorption capacity increased by 105.5%.