A　coupling　bioreactor　based　on　the　flow　separate　and　multi-phase　reaction　principle　is　designed　to　study　the　nutrient　removal　and　the　effects　of　the　sludge　reduction.　And　a　dynamic　circular　bioreactor　is　developed　on　the　basis　of　the　theory　to　investigate　whether　the　sludge　in　the　porous　carriers　has　been　decompounded　in　anaerobic　environment　or　not.　The　influent　loading　of　COD　is　from　0.80　to　1.20　kg/(m3·d),　the　concentration　of　NH4+-N　and　TN　is　from　70　to　90　mg/L　and　75　to　110　mg/L　respectively,　hydraulic　retention　time　and　temperature　in　bioreactor　is　8　hours　and　25°C.　The　results　show　that　the　removal　rate　of　TN　is　higher　and　the　production　of　sludge　is　lower　in　the　progress　of　micro-aeration+anoxic+aeration　than　those　of　whole　aeration　progress.　The　concentration　of　TN,　TP　and　TC　all　increase　and　CH4　is　produced　in　the　dynamic　circular　bioreactor.　It　can　conclude　that　the　sludge　held　back　by　the　porous　carriers　was　digested　in　anaerobic　environment　inside　the　porous　carriers.　Thereby,　the　sludge　production　is　low　and　even　has　no　sludge.