This　work　presented　an　innovative　strategy　for　short-chain　fatty　acids　(SCFAs)　production　from　anaerobic　waste　activated　sludge　(WAS)　fermentation　via　heat　assisted　potassium　ferrate　(PF)　pretreatment.　Results　showed　that　under　optimal　pretreatment　condition　(55　°C　+　0.1　g　PF/g　TSS),　SCFAs　production　achieved　4068.4　mg　COD/L　with　acetic　acid　reaching　1766.1　mg　COD/L,　significantly　higher　than　those　of　the　control　(77.39　mg　COD/L,　only　acetic　acid　contained)　as　well　as　individual　heat　(2930.8　and　1203.5　mg　COD/L)　and　individual　0.1　g　PF/g　TSS　(1970.1　and　982.7　mg　COD/L)　pretreatment　groups.　Mechanism　analysis　revealed　that　heat-assisted　PF　pretreatment　aggravated　WAS　disintegration　by　facilitating　the　disruption　of　EPS　and　cells,　hence　accelerating　organics　release　from　sludge　flocs　to　the　supernatant.　Besides,　the　biodegradability　of　released　substances　was　also　improved　thereby　providing　quantities　of　directly　available　substrates　for　hydrolysis　and　acidification　process.　Analysis　of　key　enzymes　involved　in　SCFAs　accumulation　showed　that　heat-assisted　PF　pretreatment　promoted　the　relative　bioactivities　of　protease,　butyrate　kinase　(BK)　and　acetate　kinase　(AK)　by　51.6%,　39.2%　and　155.6%　compared　to　the　control　respectively,　while　suppressing　the　bioactivity　of　coenzyme　F420.　Microbial　community　analysis　demonstrated　the　enrichment　of　Proteobacteria　and　Firmicutes,　which　were　related　to　SCFAs　accumulation.　Meanwhile,　in　genus　level,　hydrolytic　bacteria　(e.g.,　Acinetobacter　sp.),　acidification　bacteria　(e.g.,　Petrimonas　sp.)　and　iron-reducing　bacteria　(e.g.,　Romboutsia　sp.)　were　enriched　while　SCFAs　consuming　bacteria　(e.g.,　Candidatus_Competibacter　sp.)　were　inhibited.　©　2022　Elsevier　Ltd