Based　on　the　principle　of　displacement　and　multi-phase　biological　reactions,　a　coupled　bioreactor　is　developed,　and　the　treatment　performance　of　wastewater　is　studied.　Results　show　that　when　the　coupled　bioreactor　influent　COD　loading　rates　inrease　from　0.43　kg/(m3·d)　to　1.42　kg/(m3·d),　the　effluent　COD　is　less　than　60　mg/L;　hydraulic　retention　time　(t),　DO,　and　the　sludge　recycle　ratio　(R)　can　affect　the　treatment　efficiency　of　the　coupled　bioreactor,　with　the　parameters　in　this　study.　When　t=11　h,　ρ(DO)=4.0　mg/L,　and　R=1,　the　average　removal　rates　of　COD,　NH4+-N,　and　TN　are　87.8%,　98.7%,　58.4%,　respectively,　which　is　a　good　removal　result.