Recently,　Step-scheme　(S-scheme)　photocatalysts　possess　great　prospects　because　of　the　unique　charge　transport　route　and　high　efficiency　of　charge　separation　in　photocatalysis.　Herein,　binary　Znln2S4/pyrene-benzene　polymer　(ZIS-PyP)　S-scheme　heterojunction　was　fabricated　by　an　in-situ　method.　The　resulting　ZIS-PyP　exhibits　an　excellent　photocatalytic　H2　evolution　rate　of　54　μmol　h−1　which　is　2.5　and　10.8-fold　than　pure　ZnIn2S4　and　PyP,　respectively.　The　trapping　agent　experiments　reveal　the　main　active　species　are　·O2−　and　h+　in　the　TCH　degradation　reaction.　The　characteristic　experiments　and　DFT　calculations　were　used　to　elucidate　the　photocatalytic　mechanism.　The　average　hydrogen　adsorption　free　energy　of　ZIS-PyP-H　is　determined　to　be　−1.51　eV,　smallest　than　that　of　ZIS-H　and　PyP-H,　which　indicates　the　most　favorable　for　hydrogen　mass　transfer　in　ZIS-PyP.　Driven　by　band　bending,　built-in　electric　field　and　Coulombic　repulsion,　a　unique　electronic　transmission　along　S-scheme　route　between　ZnIn2S4　and　PyP　was　formed.　Therefore,　the　powerful　electrons　left　in　the　LUMO　of　PyP　and　strong　holes　in　VB　of　ZnIn2S4　attended　to　reactions,　ultimately　achieved　an　optimal　hydrogen　production　and　TCH　degradation　efficiency　in　ZIS-PyP　S-scheme　system.　©　2023　Elsevier　B.V.