Anaerobic/Aerobic/Anoxic　(AnOA)　process　utilizes　endogenous　denitrification　to　remove　nitrogen.　However,　low　endogenous　denitrification　activity　critically　restricts　its　application　owing　to　insufficient　carbon　sources.　In　this　study,　a　novel　control　strategy　employing　anaerobic/aerobic/anoxic/aerobic/anoxic　(AOAOA)　mode　was　introduced　to　treat　low　Carbon/Nitrogen　(C/N)　ratio　municipal　wastewater　over　262　days.　The　concentration　of　total　inorganic　nitrogen　(TIN)　was　only　3.9　±　2.0　mg/L　in　the　effluent,　with　a　high　nitrogen　removal　efficiency　(NRE)　of　94.3　%.　The　relative　abundance　of　Candidatus　Competibacter　increased　from　1.2　%　to　2.3　%,　ensuring　an　efficient　endogenous　denitrification　process.　Additionally,　Candidatus　Brocadia　enriched　from　0.02　%　to　0.6　%,　contributing　to　63.1　%　nitrogen　removal　during　the　anoxic　stage　in　Phase　Ⅲ.　This　study　presents　a　promising　approach　for　enhancing　endogenous　denitrification　and　anammox　in　the　AnOA　process,　contributing　to　sustainable　wastewater　treatment.　©　2024