In　order　to　strengthen　the　efficiency　of　the　advanced　nitrogen　and　phosphorus　removal　process　of　three-dimensional　biofilm-electrode　reactor　(3DBER)　and　improve　the　quality　of　secondary　effluent　from　wastewater　treatment　plant,　a　three-dimensional　biofilm-electrode　reactor　with　sulfur/sponge　iron　mixed　fillers　(3DBER-S-Fe)　composite　denitrification　and　phosphorus　removal　process　was　constructed　using　sulfur/sponge　iron　mixed　fillers,　studies　were　conducted　under　different　ρ(C)/ρ(N),　I　and　hydraulic　retention　time　(HRT)　conditions　to　explore　the　effects　on　the　performance　of　advanced　removal　of　nitrogen　and　phosphorus.　Finally,　biofilms　were　taken　from　the　fillers　and　cathode　to　build　the　bacterial　16S　rRNA　gene　clone　library　by　adopting　the　high-throughput　sequencing　technologies.　Results　show　that　under　the　condition　of　ρ(C)/ρ(N)=2,　I=150　mA　and　HRT=4　h,　the　total　nitrogen　(TN)　and　total　phosphorus　(TP)　removal　rate　of　3DBER-S-Fe　can　reach　to　85.59%　and　97.43%　respectively.　Furthermore,　the　removal　efficiency　of　nitrogen　and　phosphorus　is　strengthened　by　properly　increasing　anyone　of　the　three　conditions.　The　largest　proportion　is　Thiobacillus　bacteria　that　can　use　elemental　sulfur　as　its　electron　donor　which　separately　accounts　for　40.62%　and　44.75%　of　the　bacterial　community　on　the　fillers　and　cathode,　and　the　proportion　of　Rhodocyclaceae　bacteria　which　can　use　elemental　hydrogen　as　its　electron　donor　reaches　more　on　the　latter.　Therefore,　the　result　of　high　nitrogen　removal　efficiency　of　the　3DBER-S-Fe　mainly　depends　on　the　interaction　of　hydrogen　autotrophic　denitrification　and　sulfur　autotrophic　denitrification,　and　the　process　of　hydrogen　autotrophic　denitrification　mainly　occurrs　on　the　cathode.　©　2016,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.