Gettingalongwiththeimprovementofgreencommunications,theenergyefficiency(EE)ofwirelessnetworkbecomesmoreandmoreimportant.However,inmulti-relay-assistedsystems,therelatedworkobviouslydependsontheend-to-endperformance,whereasEEofrelayshasnotattractedenoughattention.Theauthorsproposeanorthogonalfrequencypisionmultiplexing(OFDM)multi-relaysystembasedonamplifyandforward(AF)mode.TakingincorporatingEEandremainingenergyasfactor,decisioncriteriaofattendingcooperationisdesigned.TheEEbasedasynchronouspoweriterationmethodispresented,andtheexistenceandconvergenceofnashequilibrium(NE)isproven.Furthermore,ajointalgorithminsubcarrierpairing,relayselectionandpowerallocationisgiven.Geneticalgorithm(GA)anditerationmethodareintegratedtoimprovetheconvergencespeedadditionally.SimulationdemonstratestheobviousimprovementofEE,decreaseofpowerconsumptionandincreaseoflifetimeinrelaysofthisalgorithmwiththeconstraintofminimumdatatransmissionrate.