Two-dimensional　(2D)　titanium　carbide　(Ti3C2Tx)　with　high　electrical　conductivity　and　large　active　surfaces　has　attracted　extensive　attention　in　recent　years.　Here,　in　order　to　address　the　fire　safety　and　poor　electromagnetic　shielding　performance　of　polystyrene　(PS),　a　highly　effective　cetyltrimethyl　ammonium　bromide-multi-wall　carbon　nanotubes@Ti3C2Tx　(C-MWCNT@Ti3C2Tx)　bilayer　was　deposited　on　PS　sphere　to　achieve　PS@C-MWCNT@Ti3C2Tx　(PCT)　composites　for　improving　its　fire　safety　and　electromagnetic　shielding　performances.　In　addition,　Ti3C2Tx　and　γ-propyl-trimethoxysilane　(KH550)　were　adopted　to　modify　silicon　wrapped　ammonium　polyphosphate　(SiAPP-NH2@Ti3C2Tx)　via　the　microencapsulation　strategy.　Finally,　the　SiAPP-NH2@Ti3C2Tx　was　incorporated　into　PCT　composites　to　fabricate　excellent　fire-resistant　PS　composites,　i.e.　PCTS.　The　obtained　results　demonstrated　that　Ti3C2Tx　not　only　promoted　the　thermal　stability　and　fire　safety　but　also　enhanced　the　electromagnetic　shielding　performance　of　PS.　For　instance,　the　PS　composite　with　three　number　of　C-MWCNT@Ti3C2Tx　bilayers　(PCTS3)　exhibited　dramatically　lowest　the　peak　of　heat　release　rate　(528　kW/m2)　and　highest　electromagnetic　shielding　effectiveness　value　(11　dB),　indicative　of　the　excellent　flame　retardant　and　considerable　electromagnetic　shielding　properties.　This　work　sheds　light　on　the　design　of　multifunctional　multi-layer　structured　polymer　composites.　©　2022　Elsevier　Ltd