To　strengthen　the　removal　TN　for　wastewater　treatment　plant　(WWTP)　effluent,　the　performance　and　bacterial　community　of　a　coupling　3-dimensional　biofilm-electrode　with　sulfur　autotrophic　denitrification　technology　(3DBER-S)　was　investigated　under　different　operating　condition　experiments　and　16S　rDNA　clone　library.　It　was　found　that　the　influences　of　electric　current　and　hydraulic　retention　time　(HRT)　were　obvious　on　the　proportion　of　hydrogen　and　sulfur　autotrophic　denitrification　process　in　3DBER-S,　but　there　was　no　significant　impact　on　the　denitrification　performance.　When　CODCr/TN　(C/N)　was　1　and　NO3--N　concentration　was　35　mg/L　in　the　influent,　NO3--N　and　TN　removal　rates　were　above　80%　and　74%　respectively　under　conditions　of　electric　current　of　300　mA　and　HRT　of　4　h.　The　analysis　of　16S　rDNA　clone　library　showed　that　the　dominant　populations　were　β-Proteobacteria　(47.89%)　in　the　biofilm　of　3DBER-S.　52.94%　of　the　β-Proteobacteria　consisted　of　a　bacteria　similar　to　Thauera　that　could　perform　denitrification.　Moreover,　the　bacteria　similar　to　Thiobacillus　and　Acidovorax　accounted　for　17.65%　and　14.71%　respectively　of　the　β-Proteobacteria,　which　can　use　sulfur　and　hydrogen　as　an　electron　donor　for　denitrification　respectively.　There　is　a　mutual　complementation　among　heterotrophic,　hydrogen　and　sulfur　autotrophic　denitrification　processes,　which　supply　3DBER-S　with　enough　electron　donors.　Then　the　stable　and　high-performance　nitrogen　removal　can　be　maintained　under　different　operating　conditions,　even　if　the　carbon　source　of　the　influent　is　insufficient.　©,　2015,　Editorial　department　of　Molecular　Catalysis.　All　right　reserved.