Granular　activated　carbon　(GAC)　as　an　economic　and　robust　amorphous　material　could　facilitate　the　syntrophic　metabolism　of　acetogenesis　and　methanogenesis　during　anaerobic　digestion　of　post-consumer　substrates.　In　this　study,　influences　of　supplementing　GAC　on　anaerobic　co-digestion　of　brewery　waste　activated　sludge　and　food　waste　for　the　production　of　methane　were　investigated　by　analysing　the　VFA　production,　ammonia　concentration,　pH,　oxidation　reduction　potential,　and　electrical　conductivity.　Our　data　showed　that　a　45%　increase　in　methane　production　with　adding　1.5%　(g/g)　GAC　was　achieved.　The　maximum　amount　of　478　mL　CH4/g　volatile　solids　(VS)added　was　recorded　along　with　64%　VS　removal　efficiency　under　a　high　ammonia　concentration　of　1420　mg　L−1.　Moreover,　the　analysis　of　scanning　electron　microscopy　exhibited　the　formation　of　biofilms　with　the　supplement　of　GAC.　Our　results　elucidate　that　GAC　evidently　enriched　activities　of　hydrolysis　and　acetogenesis　and　enhanced　the　electron　transfer　efficiency　for　methanogenesis,　which　improved　the　production　of　methane　significantly.　Our　results　also　demonstrate　that　the　supplementation　of　GAC　is　an　efficient　method　for　the　enhancement　of　biogas　production　from　post-consumer　wastes.　©　2020