In　view　of　the　problems　such　as　the　long　time　of　biofilm　formation　and　the　low　removal　efficiency　of　styrene　in　a　bio-trickling　filter,　the　degradation　can　be　enhanced　by　the　modified　method　of　start-up　and　the　addition　of　surfactants.　To　investigate　the　performance　of　the　horizontal　bio-trickling　filter　at　the　start-up　stage,　high-concentration　styrene　gas-liquid　phase　combined　start-up　method　was　adopted　and　a　small　proportion　of　glucose　was　added　into　the　nutrient　solution.　Domesticated　compound　strains　were　inoculated.　Performance　of　the　horizontal　bio-trickling　filter　was　enhanced　by　adding　Tween-80,　and　its　mechanism　was　studied.　Results　show　that　the　start-up　time　of　the　horizontal　bio-trickling　filter　is　only　5　d.　When　the　inlet　concentration　of　styrene　is　700　-　1　100　mg/m3　and　the　EBRT　is　35　-　40　s,　the　addition　of　Tween-80　significantly　increases　the　removal　efficiency　of　styrene　by　about　10%.　Degradation　of　styrene　in　the　horizontal　bio-trickling　filter　is　enhanced　in　the　presence　of　Tween-80　because　the　solubility　of　styrene　can　be　improved　in　the　horizontal　bio-trickling　filter　system,　and　the　content　of　extracellular　polymeric　substances　and　the　proportion　of　dominant　bacterial　community　(Proteobacteria)　increases.　In　addition,　the　shedding　of　aging　biofilm　is　accelerated.　©　2023　Beijing　University　of　Technology.　All　rights　reserved.