Epoxy　resin　is　a　widely　utilized　thermosetting　polymer,　however,　its　flammability　and　brittleness　significantly　hinder　its　broader　application　and　development.　This　study　introduces　a　novel　polyphosphazene　modified　iron-based　montmorillonite　(Fe-OMMT@PZS),　aimed　at　enhancing　the　characteristics　of　advanced　EP　composites.　These　results　revealed　that　Fe-OMMT@PZS　was　not　only　evenly　dispersed　within　the　EP　matrix,　but　also　enhanced　the　thermal　stability　and　fire　resistance　of　EP　composites.　In　comparison　to　pure　EP,　the　EP/Fe-OMMT@PZS　10　composites　exhibited　reductions　of　57.1%,　20.5%,　50%,　44.4%,　60%,　and　56%　in　the　peak　heat　release　rate　(PHRR),　total　heat　release　(THR),　peak　smoke　production　rate　(PSPR),　total　smoke　production　(TSP),　peak　carbon　monoxide　production　rate　(PCO),　and　peak　carbon　dioxide　production　rate　(PCO2),　respectively.　The　outstanding　fire　safety　performance　was　attributed　to　catalytic　carbonization　induced　by　metal　compounds　and　phosphates,　the　capture　of　free　radicals　in　gas　phase,　and　dilution　effect　by　non-combustible　gases,　and　the　physical　barrier　created　by　the　Fe-OMMT　nanosheets.　Furthermore,　when　the　Fe-OMMT@PZS　content　reached　3　wt%,　the　composites　demonstrated　significant　improvements　in　mechanical　properties,　with　increases　of　58.8%,　94.6%　and　161.9%　in　elongation　at　break,　tensile　strength　and　tensile　modulus,　respectively,　demonstrating　outstanding　toughness　enhancement.　This　research　provides　an　effective　strategy　for　tackling　the　balance　between　mechanical　properties　and　flame　resistance.　©　2025　Elsevier　Ltd