This　study　focused　on　the　problem　that　simultaneous　nitrogen　and　phosphorus　removal　cannot　be　achieved　in　current　urban　sewage　treatment　systems.　To　address　this,　a　pilot　system　was　developed　to　first　use　immobilized　biologically　active　fillers　to　remove　nitrogen,　and　then　use　activated　sludge　to　independently　remove　phosphorus.　The　goal　was　to　maximize　the　effectiveness　of　biological　phosphorus　removal.　This　study　mainly　aimed　at　analyzing　the　post-independent　phosphorus　removal　characteristics　and　mechanisms;　the　composition　of　the　phosphorus　removing　bacteria;　and　the　contribution　rate　of　the　system.　The　effluent　PO43--P　of　the　system　remained　stable　at　0.15-0.2　mg　L-1,　with　the　phosphorus　removal　anaerobic　tank　maintaining　a　＂micro-release＂　state.　When　the　hydraulic　retention　time　(HRT)　of　the　aerobic　phosphorus　removal　tank　was　reduced　to　1　h,　the　contribution　rate　of　the　aerobic　phosphorus　removal　bacteria　decreased　from　28.42%　to　16.68%;　the　contribution　rate　of　the　denitrifying　phosphorus　removal　bacteria　increased　from　72.58%　to　83.32%;　and　the　abundance　of　the　dominant　bacteria　Dechloromonas　and　Thaurea　significantly　increased.　The　phosphorus　removal　system　provides　a　new　approach　for　deep　phosphorus　removal　in　main　municipal　wastewater　systems.　(C)　2021　Institution　of　Chemical　Engineers.　Published　by　Elsevier　B.V.　All　rights　reserved.