Abstract: In order to evaluate the adsorption separation performance of carbon molecular sieves,the enrichment and separation test of CH4/ N2 mixture by pressure s wing adsorption device were measured.The enrichment effects for different concentration of CH4/ N2 mixture affected by BM1 404 carbon molecular sieve were studied.The influences of different adsorption time, finished product gas exhaust flow rate on concentration,recovery rate and production capacity affected to enrichment effects were als 0 researched.The results showed that the separation effect was the best when the adsorption time was 150 s,finished product gas exhaust flow rate was 4. 20 m L / min,C H4 content of coalbed methane could be improved from 35% to 68. 10%,the recovery rate reached 67. 30%. The BM1404 carbon molecular sieve was suitable for CH4/ N2 mixture separation,which could make the concentration of methane concentrated from 18% to 45. 25%,35% to68. 10%,71% to 86.80%, BM1404 carbon molecular sieves ha d better separation effect for different coalbed methane concentration.