Herein,　polyphosphazene　nanoparticle　(PPN)　functionalized　MoS2　nanosheets　have　been　successfully　fabricated　through　a　novel　two-step　method,　involving　a　simple　ball　milling　of　bulk　MoS2　powders　to　acquire　exfoliated　MoS2　nanolayer,　followed　by　high　temperature　polymerization　to　achieve　MoS2@PPN　nanohybrids.　The　incorporation　of　P　and　N　atoms　could　efficiently　reduce　the　stacking　of　MoS2　nanolayers　and　form　large　number　of　active　sites.　It　is　noted　that　introducing　well-characterized　MoS2@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/MoS2@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　MoS2　ultrathin　nanosheets,　as　well　as　improved　interface　interaction　between　MoS2@PPN　and　EP　matrix.　©　2018　Elsevier　Ltd