Abstract: In order to reduce environment pollution,improve coalbed methane recovery and increase energy re-serve,this paper based on the principles of coalbed methane geology and biogenic gas,proposed a new viewpoint of multi-application of CO₂ injection into coal bed.The studied results show that coal beds can be used as CO₂ res-ervoirs because coal has strong adsorption capacity for CO₂;and CO₂ injection into coal beds can improve coalbed methane recovery because coal is preference for CO₂ adsorption and postponement for methane(CH₄) adsorption;and CH₄,which is a new energy generated by methanogens from CO₂,is the beneficial complement of the energy.It is obvious that CO₂ injection into coal beds can not only reduce the green-house gas emission and improve coalbed methane recovery,but also provide the basic material to new energy:biogenic methane.