Hydrophobic　volatile　organic　compounds　(VOCs)　pose　a　challenge　to　the　removal　efficiency　in　biotrickling　filters　(BTFs).　The　addition　of　relatively　hydrophilic　substances　presents　a　promising　approach　for　enhancing　the　elimination　of　hydrophobic　VOCs.　In　this　study,　toluene　was　introduced　into　the　BTF　system　alongside　m-xylene,　and　their　mixing　ratios　were　changed　to　explore　the　interactions　and　mechanisms　under　different　conditions.　The　result　showed　that　the　most　pronounced　synergistic　interaction　occurred　when　the　mixing　concentration　ratio　of　m-xylene　and　toluene　was　2:1.　The　removal　efficiency　(RE)　of　m-xylene　increased　from　88%　to　97%,　and　the　elimination　capacity　(EC)　of　m-xylene　changed　from　64　to　72　g　m-　3　h-1.　Under　this　condition,　there　was　a　notable　increase　in　biomass,　extracellular　polymeric　substance　(EPS)　content,　and　relative　hydrophobicity.　Microbial　diversity　was　enhanced　observably　with　Berkeleyces　and　Mycobacterium　potentially　playing　a　positive　role　in　co-degradation.　Meanwhile,　microbial　metabolic　function　prediction　indicated　a　significant　enhancement　in　metabolic　functions.　Therefore,　the　introduction　of　relatively　hydrophilic　VOCs　represents　an　effective　strategy　for　enhancing　the　removal　of　hydrophobic　VOCs　in　the　BTFs.