Anammox　is　a　promising　biotechnology　for　nitrogen　removal　and　gaining　popularity　in　mainstream　wastewater　treatment.　The　efficient　and　low　energy-consumed　elimination　of　the　intrinsic　byproduct　nitrate　in　anammox-mediated　process　is　still　a　tough　barrier　and　urgently　demands　resolving.　To　explore　a　newly　green　alternative　for　advanced　nitrogen　removal　from　domestic　sewage,　this　study　proposed　a　novel　Integrated　Anammox,　Fermentation　and　Denitrification　(IAFD)　process.　After　215-day　operation,　total　inorganic　nitrogen　(TIN)　removal　efficiency　markedly　increased　from　72.6%　to　94.1%　and　effluent　TIN　dropped　from　7.9　mg　L-1　to　1.8　mg　L-1　with　influent　TIN　of　56　mg　L-1.　Through　in-situ　activated　sludge　fermentation,　37.341　mg　COD.L-1.d-　1　organics　was　yielded,　causing　a　COD/NO3--N　of　8.9,　Soluble　protein　(63.8%),　polysaccharide　(10.6%)　and　acetic　acid　(13.9%)　were　primary　components.　Candidatus_Brocadia　(0.8%)　and　Candidatus_Competibacter　(4.6%)　were　dominant　functional　bacteria,　which　contributed　81.1%　and　18.9%　to　nitrogen　elimination,　respectively.　Robust　anammox　(3.37　mg　N.g　VSS-　1.h-1),　fermentation-assisted　denitrification　and　denitritation　synergistically　boosted　N　removal.　The　novel　process　required　no　external　carbon,　reduced　59.5%　aeration　and　35.8%　external　sludge.　The　novel　process　showed　significantly　environmental　and　economical　advantages　of　low　operation　expenses　and　energy　cost　with　no　external　carbon　requirement,　59.5%　aeration　and　35.8%　external　sludge　reduction.　This　work　provided　an　energy-neutral　and　sustainable　scheme　for　the　advanced　nitrogen　removal　of　municipal　wastewater　and　sludge　disposal　in　WWTPs.