Herein,　polyphosphazene　nanoparticle　(PPN)　functionalized　MoS　2　nanosheets　have　been　successfully　fabricated　through　a　novel　two-step　method,　involving　a　simple　ball　milling　of　bulk　MoS　2　powders　to　acquire　exfoliated　MoS　2　nanolayer,　followed　by　high　temperature　polymerization　to　achieve　MoS　2　@PPN　nanohybrids.　The　incorporation　of　P　and　N　atoms　could　efficiently　reduce　the　stacking　of　MoS　2　nanolayers　and　form　large　number　of　active　sites.　It　is　noted　that　introducing　well-characterized　MoS　2　@PPN　nanohybrids　significantly　improve　the　flame　retardancy　of　epoxy　resin　(EP),　i.e.,　30.7%　and　23.6%　reductions　in　peak　heat　release　rate　and　total　heat　release,　respectively.　The　friction　coefficients　testing　results　reveal　that　the　EP/MoS　2　@PPN1.0　composite　exhibits　the　lowest　friction　coefficient　value　and　volume　wear　rate.　The　excellent　properties　of　these　EP　composites　result　from　synergetic　coupled　effect　between　PPN　and　MoS　2　ultrathin　nanosheets,　as　well　as　improved　interface　interaction　between　MoS　2　@PPN　and　EP　matrix.　©　2018　Elsevier　Ltd