Achieving　simultaneous　semi-partial　nitrification　and　deep　phosphorus　removal　is　a　preferred　process　technology　for　Anammox　pretreatment.　In　this　study,　semi-partial　nitrification　combined　with　in-situ　phosphorus　recovery　(PNPR)　was　used　to　treat　municipal　wastewater.　The　SRT　conflict　between　the　nitrification　and　phosphorus　removal　was　resolved　by　in-situ　phosphorus　recovery　every　20　cycles　of　Anaerobic/Oxid,　and　a　supernatant　with　more　than　10　times　the　influent　phosphorus　concentration　was　obtained,　thus　achieving　bio-enhanced　phosphorus　removal　and　recovery　with　satisfactory　semi-partial-nitrification　effluent.　Interestingly,　the　results　showed　that　phosphorus　removal　and　recovery　process　could　improve　the　activity　of　AOB.　The　PNPR　system＇s　nitrite　accumulation　rate　(NAR)　and　phosphorus　removal　rate　(PRR)　were　more　than　90%　each,　whereas　the　relative　abundance　of　AOB　and　PAOs　increased　from　0.04%　to　0.74%　and　from　0.25%　to　0.70%,　respectively　(P　＜　0.01).　Furthermore,　on　average,　the　NO2--N-eff/NH4+-Neff　value　was　1.96,　which　laid　the　foundation　for　the　subsequent　anammox　treatment.