This　study　constructed　two　thiosulfate-driven　autotrophic　denitrification　biofilters　filled　with　volcanic　rock　(VRBF),　sponge　iron　and　volcanic　rock　(SIVR-BF),　respectively.　The　nitrate　removal　load　(3200　g/m(3)/d)　and　efficiency　(98　%)　of　SIVR-BF　were　higher　than　those　of　VR-BF.　The　removal　of　phosphate　in　SIVR-BF　was　mainly　through　forming　FePO4　and　Fe-3(PO4)(2)(OH)(2).　Sulfur　and　iron　cycles　in　SIVR-BF　contributed　to　Fe　(II)/Fe　(III)　electron　shuttle,　as　well　as　S2,　S0,　Sn2　electron　buffer　and　energy　storage,　which　improved　nitrate　removal　and　electron　utilization.　The　formation　of　multi-path　collaborative　denitrification　dominated　by　sulfur　autotrophic　denitrification　(64.2　similar　to　89.6　%)　in　SIVR-BF.　The　other　denitrification　pathways,　such　as　iron　autotrophic　denitrification,　which　buffered　pH　and　reduced　sulfate　production.　Thiobacillus　(38.6　%)　and　Ferritrophicum　(25.3　%)　were　the　dominant　genus　of　VR-BF　and　SIVR-BF,　respectively,　which　played　crucial　roles　in　autotrophic　denitrification　of　iron　and　sulfur.　SIVR-BF　was　a　promising　process　to　realize　iron-sulfur　coupling　autotrophic　denitrification　and　phosphate　removal.