Carbon-based　composite　materials　have　garnered　widespread　attention　in　the　field　of　personal　thermal　management　(PTM).　In　these　applications,　constructing　conductive　fillers　with　a　highly　cross-linked　network　is　key　to　achieving　the　rapid　electrothermal　conversion　of　materials.　Herein,　a　novel　carbon-based　composite　material　is　successfully　developed　using　screen　printing　technology,　with　a　waterborne　polyurethane　(WPU)　matrix　embedded　with　carbon　nanotubes　(CNTs)　and　calcein-modified　graphene　nanosheets　(CAG).　Due　to　the　strong　π–π　conjugation　interactions　present　in　the　highly　cross-linked　carbon-based　network,　the　resulting　CAG-CNTs/WPU　composite　forms　a　3D　conductive　network,　which　not　only　demonstrates　a　significant　synergistic　effect　but　also　facilitates　efficient　transport　of　electrons　and　phonons.　Experimental　results　show　that　the　CAG-CNTs/WPU　composite　possesses　excellent　electrothermal　conversion　properties　and　an　upper　high　thermal　conductivity　(3.10　W　m−1　K−1).　At　a　low　voltage　of　5　V,　the　composite　exhibits　a　rapid　response,　increasing　to　50　°C　in　20　s.　This　research　not　only　highlights　the　importance　of　adopting　environmentally　friendly　preparation　methods　but　also　emphasizes　the　synergistic　role　played　by　2D　graphene　nanosheets　and　1D　CNTs　in　building　an　efficient　3D　electrothermal　network,　which　has　significant　scientific　and　application　value　in　advancing　PTM　applications.　©　2024　Wiley-VCH　GmbH.