Tar　generated　as　a　by-product　during　biomass　gasification　contains　a　high　concentration　of　refractory　organic　matters.　In　this　study,　a　hybrid　upflow　anaerobic　sludge-biochar　bed　reactor　was　established　for　tar　treatment,　and　the　methane　yield　was　120–154　NmL-CH4/g-CODinf,　20–30%　higher　than　the　control　reactor.　COD　removal　and　methane　production　significantly　decreased　in　both　reactors　when　the　influent　tar　concentration　was　doubled　from　4954　mg-COD/L　to　9964　mg-COD/L.　When　the　influent　concentration　was　reduced,　the　biochar　packed　reactor　showed　a　faster　recovery.　Batch　tests　confirmed　that　higher　tar　concentration　inhibited　methane　production　and　induced　longer　lagphase.　Biochar　addition　effectively　relieved　the　inhibition　and　prolonged　the　retention　of　organic　matters.　SEM　observation　and　16S　rRNA　analysis　suggested　that　biochar　also　acted　as　the　microbe＇s　carrier,　and　promoted　the　growth　of　some　microbes.　The　results　of　this　study　provide　new　ideas　for　tar　treatment.　©　2022　Elsevier　Ltd