With　the　development　of　modern　electronics,　especially　the　next　generation　of　wearable　electromagnetic　interference　(EMI)　shielding　materials　requires　flexibility,　ultrathin,　lightweight　and　robustness　to　protect　electronic　devices　from　radiation　pollution.　In　this　work,　the　flexible　and　ultrathin　dopamine　modified　MXene@cellulose　nanofiber　(DM@CNF)　composite　films　with　alternate　multilayer　structure　have　been　developed　by　a　facile　vacuum　filtration　induced　self-assembly　approach.　The　multilayered　DM@CNF　composite　films　exhibit　improved　mechanical　properties　compared　with　the　homogeneous　DM/CNF　film.　By　adjusting　the　layer　number,　the　multilayered　DM3@CNF2　composite　film　exhibits　a　tensile　strength　of　48.14　MPa　and　a　toughness　of　5.28　MJ·m−3　with　a　thickness　about　19　µm.　Interestingly　that,　the　DM@CNF　film　with　annealing　treatment　achieves　significant　improvement　in　conductivity　(up　to　17264　S·m−1)　and　EMI　properties　(SE　of　41.90　dB　and　SSE/t　of　10169　dB·cm2·g−1),　which　still　maintains　relatively　high　mechanical　properties.　It　is　highlighted　that　the　ultrathin　multilayered　DM@CNF　film　exhibits　superior　EMI　shielding　performance　compared　with　most　of　the　metal-based,　carbon-based　and　MXene-based　shielding　materials　reported　in　the　literature.　These　results　will　offer　an　appealing　strategy　to　develop　the　ultrathin　and　flexible　MXene-based　materials　with　excellent　EMI　shielding　performance　for　the　next　generation　intelligent　protection　devices.　[Figure　not　available:　see　fulltext.].　©　2023,　Higher　Education　Press.