The　influence　of　ultrasound　(US)　and　potassium　permanganate　(KMnO4)　co-pretreatment　on　anaerobic　digestion　of　waste　activated　sludge　(WAS)　was　investigated　in　this　survey.　Results　showed　that　KMnO4　(0.3　g/g　TSS)　cooperated　with　US　(1　W/mL,　15　min)　pretreatment　significantly　increased　the　cumulative　methane　yield　to　174.44　+/-　3.65　mL/g　VS　compared　to　the　control　group　(108.72　+/-　2.56　mL/g　VS),　solo　US　(125.39　+/-　2.56　mL/g　VS),　and　solo　KMnO4　pretreatment　group　(160.83　+/-　1.61　mL/g　VS).　Mechanistic　investigation　revealed　that　US　combined　with　KMnO4　pretreatment　effectively　disrupted　the　structure　of　extracellular　polymeric　substances　and　cell　walls　by　generating　reactive　radicals,　accelerating　the　release　of　organics　and　hydrolytic　enzymes　as　well　as　improving　the　biodegradability　of　soluble　organics.　Modeling　analysis　illustrated　that　the　biochemical　methane　potential　and　hydrolysis　rate　of　WAS　were　enhanced　under　US　+　KMnO4　pretreatment.　Microbial　community　distribution　indicated　that　the　co-pretreatment　of　US　and　KMnO4　elevated　the　total　relative　abundance　of　functional　microorganisms　associated　with　anaerobic　digestion　(22.01　%)　compared　to　the　control　(10.69　%),　US　alone　(12.24　%)　and　KMnO4　alone　(16.20　%).