Excessive　discharge　of　nutrients　from　wastewater　treatment　plants　(WWTPs)　is　an　important　pollutant　source　of　eutrophic　water　bodies.　In　this　work,　three　electrochemically　integrated　horizontal　flow　constructed　wetlands　(E-HFCWs)　were　developed　for　advanced　nutrients　removal　from　WWTPs　effluent　with　different　S/N　ratios.　In　E-HFCWs,　PO43-,　NO3--N　and　TN　removal　percentages　at　current　of　0.2　A　and　hydraulic　retention　time　(HRT)　of　24　h　did　not　differ　significantly　as　S/N　ratios　altered.　When　fed　with　low,　middle　and　high　concentrations　of　SO42--S　wastewater　during　this　period,　PO43--P　removal　percentages　respectively　reached　99.3　%+/-　0.9　%,　99.2　%+/-　1.1　%　and　99.0　%+/-　1.4　%,　NO3--N　removal　percentages　respectively　reached　99.5　%+/-　0.5　%,　99.6　%+/-　0.4　%　and　99.4　%+/-　0.8　%,　and　TN　removal　percentages　respectively　reached　92.0　%+/-　2.5　%,　90.8　%+/-　3.4　%　and　91.2　%+/-　2.7　%.　This　work　highlighted　that　sulfur　cycle　played　crucial　roles　in　improving　nitrogen　removal　stability　as　current　or　HRT　decreased　in　higher　S/N　ratio　groups.　The　formed　sulfur　ferrites　under　higher　current　or　HRT　condition　served　as　＂electron　reservoir＂,　and　would　resupply　electron　for　denitrification　when　electron　supplied　by　electrolysis　was　deficient.　In　addition,　the　higher　S/N　ratio　groups　allowed　significantly　lower　N2O　accumulation,　which　was　accordance　with　the　concept　of　carbon　neutral.　Based　on　metagenome　results,　the　occurrence　of　more　abundant　sulfur-oxidizing　denitrifying　genes　and　bacteria　(e.g.,　Thiobacillus)　in　higher　S/N　ratio　groups　under　lower　current　or　HRT　further　demonstrated　the　significant　roles　of　sulfur　cycle　in　stable　autotrophic　denitrification　performance　in　E-HFCWs.　Overall,　this　work　provides　perspective　on　the　future　practical　application　for　the　regulation　of　nitrogen　removal　stability　enhancement　and　N2O　emission　reduction　in　electrochemically　integrated　bioreactors.