Fire　safety　and　protection　are　very　important　but　still　show　a　critical　global　challenge.　Developing　smart　fire　warning　materials　with　combined　passive　flame　retardancy　and　active　fire　alarm　response　is　promising　for　reducing　or　avoiding　serious　fire　disasters.　Various　nano-fillers　(e.g.,　graphene　oxide　and　MXene)　based　composite　coatings　have　proven　to　be　effective　for　monitoring　critical　fire　risk　of　various　combustible　materials;　however,　they　still　show　some　shortages,　for　example,　high　cost,　black　color,　poor　weather　resistance　and　complicated　fabricating　process.　Here,　we　report　a　green,　cost-effective　and　large-scale　strategy　for　fabricating　water-based　3D-titania/2D-montmorillonite/1D-celluose　nanofiber　(TiO2/MMT/CNF)　hierarchical　nanocomposite　coatings　with　adjustable　color,　mechanical　robustness,　good　flame　retardancy,　long-term　weather　resistance　and　sensitive　fire　cyclic　alarming　response.　The　formation　of　strong　chemical　bonding　and　hydrogen　bonding　interactions　among　polyethylene　glycol　molecules　and　multi-scale　nano-fillers　together　with　silane　surface　modification　can　produce　good　mechanical　flexibility　(folded　crane),　surface　hydrophobicity　(water　contact　angle　of　152°)　and　exceptional　flame　resistance　(good　structure　integrity　after　120　s　flame　exposure).　Notably,　the　optimized　nanocomposite　coatings　exhibit　ultrafast　fire　alarm　response　(2　network　under　flame.　Further,　such　color-adjustable　nanocomposite　coatings　can　be　easily　fabricated　for　large-scale　production,　and　they　show　excellent　stable　flame　retardancy　and　stable　fire　cyclic　warning　response　even　after　more　than　one-year　outdoor　exposure.　This　work　provides　a　promising　and　green　fire-warning　nanocomposite　coatings　with　combined　passive-active　functionalities　for　fire　warning　and　protection.　©　2023　Elsevier　Ltd