In　order　to　exploit　and　use　the　organic　matter　in　the　fermentation　liquid,　the　study　added　various　dosage　of　AlCl3•6H2O　to　the　sludge　digestion　system　which　using　the　technology　of　Autothermal　Thermophilic　Micro-Aerobic　Digestion　(ATMAD),　the　thesis　discussed　about　the　impacts　of　aluminum　ions　(Al3+　)　on　transformation　rule　of　organic　substance,　volatile　fatty　acid　(VFA),　ammonia　nitrogen　(NH4+-N)　and　orthophosphate　(PO43--P)　in　the　course　of　ATMAD.　The　results　promoted　that　the　conversion　and　degradation　of　organic　substance　was　inhibited,　meanwhile,　the　content　and　composition　of　dissolved　organic　substance　in　sludge　digestion　solution　was　changed　when　Al3+　was　existing　in　the　system　of　ATMAD.　The　maximum　production　of　VFA　in　contrast　group　was　6.9　multiple　than　experimental　group　with　the　concentration　of　Al3+　was　1.0g/L.　When　the　process　of　ATMAD　digestion　ended,　the　concentration　of　NH4+-N　was　502.06mg/L　in　the　reactor　which　the　concentration　of　Al3+　was　1.0g/L,　in　the　contrast　group　the　concentration　of　NH4+-N　just　was　334.41mg/L.　The　activity　of　microorganisms　declined　when　Al3+　present　in　the　system　of　ATMAD.　It　can　be　concluded　that　Al3+　have　negative　impacts　on　sludge　digestion　and　stabilization.　It’s　advisable　to　avoid　adding　excessive　aluminum　ions　in　sludge　ATMAD　system　to　ensure　the　digestion　system　can　fully　produce　acid　and　release　organic　substance,　which　will　be　used　as　high-quality　carbon　for　biological　nitrogen　removal.　©　2023　Chinese　Society　for　Environmental　Sciences.　All　rights　reserved.