Graphene　oxide　(GO)-based　fire　alarm　materials　have　garnered　extensive　attention　because　the　thermal　reduction　of　GO　to　reduced　GO　(RGO)　enables　rapid　fire　warning.　However,　they　suffer　from　poor　flame　retardancy,　irreversible　fire　warning,　and　dependence　on　an　external　power　supply.　Herein,　a　GO/MXene/chitosan　aerogel　with　a　low　density　of　0.018　g　cm-3　and　good　compressibility　has　been　developed.　The　experimental　results　demonstrate　that　(i)　MXene　effectively　reduces　the　peak　and　mean　heat　release　rate　of　GO,　while　RGO　nanosheets　compensate　for　the　structural　instability　of　MXene　in　the　flame　due　to　thermal　oxidation　into　TiO2;　as　such,　long-lasting　fire　warning　(＞120　s)　has　been　achieved;　(ii)　the　reducibility　and　conductivity　of　MXene　contribute　to　the　ultrasensitive　response　of　GO,　with　a　fire　response　time　of　1　s;　and　(iii)　notably,　the　thermoelectric　effect　of　MXene　enables　the　reversible　and　self-powered　fire　warning　of　the　GO/MXene/CS　aerogel　without　an　external　power　supply.　Compared　to　pure　MXene/CS　aerogel,　the　presence　of　GO　improves　the　sensitivity　and　stability　of　self-powered　fire　warning,　owing　to　the　formation　of　the　highly　conductive　RGO　nanosheets.　The　results　of　this　work　highlight　the　cooperation　between　GO　and　MXene　in　realizing　ultrasensitive,　long-lasting,　reversible,　and　self-powered　fire　warning.　©　2024　American　Chemical　Society.