The　combustion　of　polymeric　materials　will　generate　a　mass　of　heat　and　release　poisonous　fumes,　which　not　only　hinders　the　personnel　escape　and　causes　casualties,　but　also　causes　the　environmental　contamination.　Herein,　a　novel　N–P–Co-containing　supramolecular　assembly　network　(MHCSN)　flame　retardant　was　synthesized　by　electrostatic　interaction　and　supramolecular　self-assembly　technology.　Then,　MHCSN-Ti3C2Tx　(MHCSN-TC)　hybrids　were　synthesized　by　hydrogen　bonding　induced　assembly　and　compounded　with　silicone　wrapped　ammonium　polyphosphate　(SiAPP)　to　successfully　fabricate　polylactic　acid　(PLA)/MHCSN-TC/SiAPP　composites.　PLA/MHCSN-TC/SiAPP　composites　exhibited　the　improved　flame　retardancy.　For　example,　the　introduction　of　1.0　wt%　MHCSN-TC　and　14.0　wt%　SiAPP　into　PLA　resulted　in　significant　reduction　in　the　total　heat　release　(50.1%),　peak　of　heat　release　rate　(64.1%)　and　peak　of　smoke　production　rate　(61.3%).　The　improvements　in　flame　retardance　and　smoke　suppression　of　the　PLA　composites　were　due　to　the　catalytic　carbonization　and　barrier　effect　of　the　modified　Ti3C2Tx　nanoflakes.　Meanwhile,　the　generated　phosphorus-containing　radicals　generated　by　SiAPP　captured　the　H•　and　HO•　produced　from　the　PLA　material,　and　these　phosphorus-containing　species　evolved　into　compact　expanded　char　layers.　This　work　offers　a　simple　method　to　prepare　highly　effective　flame　retardants　for　PLA.　©　2022　Elsevier　Ltd