Vast　amounts　of　electromagnetic　waves　are　generated　in　modern　society,　which　severely　endanger　human　health　and　cause　instrument　disturbance.　Furthermore,　practical　application　of　electromagnetic　shielding　polymer-based　materials　aspires　to　flame　retardancy.　Herein,　cellulose　acetate　butyrate　modified　ammonium　polyphosphate　(CAPP)　and　phosphoramide　flame　retardant　decorated　short　carbon　fiber　(MSCF)　were　synthesized　separately　and　then　simultaneously　blended　into　thermoplastic　polyurethane　(TPU)　to　prepare　a　series　of　flame　retardant　TPU　composites.　Then,　the　multi-hierarchical　flexible　TPU/CAPP/MSCF　composites　were　fabricated　via　our　self-developed　air-assisted　thermocompression　method.　The　results　revealed　that　the　TPU/CAPP/MSCF　showed　improved　thermal　stability.　Moreover,　the　TPU/10CA/2.5F　incorporated　with　10.0　wt.%　CAPP　and　2.5　wt.%　MSCF　respectively　exhibited　77.8%　and　58.6%　reduction　in　peak　of　heat　release　rate　(PHRR)　and　total　heat　release　(THR),　compared　to　those　of　pure　TPU.　In　addition,　the　TPU/10CA/2.5F　passed　the　UL-94　V-0　rating　test　and　achieved　a　higher　limit　oxygen　index　(LOI)　(27.3%)　than　pure　TPU　(21.7%).　In　the　case　of　electromagnetic　interference　shielding　effectiveness　(EMI　SE),　the　TPU/10CA/10.0F-SW　with　10　wt.%　CAPP　and　10　wt.%　MSCF　dispersed　in　the　surface　layer　and　Ti3C2Tx　MXene　intercalated　in　the　interlayer　exhibited　EMI　SE　of　43.8　dB　in　X　band　and　32.0　dB　in　K　band.　Summarily,　synergistic　effect　between　CAPP　and　MSCF　together　with　scattered　and　multiply　adsorbed　effect　of　MSCF,　MXene　and　CAPP　was　responsible　for　fire　safety　and　EMI　shielding　property　improvements.　This　work　provides　a　fascinating　strategy　for　fabricating　multi-hierarchical　flexible　TPU　composites　with　outstanding　flame　retardant　and　EMI　shielding　performances.　[Figure　not　available:　see　fulltext.].　©　2022,　Tsinghua　University　Press.