It　was　different　to　reduce　the　greenhouse　gas　(GHG)　emission　intensity　of　the　wastewater　treatment　industry　in　China,　owing　to　a　lack　of　research　and　demonstration　experience.　This　study　aims　to　predict　hyper-treated-quantity　functional　performance　and　provide　a　guidance　for　its　real　operation　to　assess　the　GHG　emission　in　a　full-scale　anaerobic-anoxic-oxic　membrane　bioreactor　(A(2)O　+　MBR)　process　in　Beijing.　The　emulated　result　illustrated　that　activated　sludge　model　(ASM)　offers　broad　applicability　to　predict　functional　performance　during　hyper-treated-quantity　operational　periods.　The　running　results　show　that　the　GHG　emission　intensity　decreased　from　1.31　to　1.24　CO(2)e/m(3),　representing　a　5.3%　decline　in　2022,　despite　the　total　annual　GHG　emission　increasing　by　42.69%　compared　to　the　levels　in　2018.　Further,　the　GHG　emission　intensity　of　CH4,　N2O,　electricity　consumption　and　chemical　agent　consumption　decreased　by　7.4%,　7.1%,　4.9%　and　12.5%,　respectively.　The　proportion　of　CH4,　N2O,　electricity　and　chemical　agent　consumption　accounted　for　20.38%,　31.89%,　47.67%　and　0.06%　of　the　total　GHG　emission,　showing　minimal　changes　compared　to　those　in　2018.　Overall,　this　research　provides　valuable　insights　to　policy-makers　regarding　water　and　carbon　issue,　assisting　them　in　identifying　to　find　low-risk　and　cost-effective　solutions　to　reduce　climate　change　impact.