Poly　(butylene　adipate-co-terephthalate)　(PBAT)　and　polylactic　acid　(PLA)　as　a　biodegradable　thermoplastic　material　have　been　expected　to　replace　traditional　undegradable　plastics.　However,　PBAT　resins　are　highly　flammable　and　have　poor　thermal　stability　and　lower　compressive　strength　performance.　For　enhancing　PBAT　compressive　strength,　thermal　stability,　and　flame　retardancy　performance,　polylactic　acid　(PLA)　resin　was　used　to　mix　with　the　PBAT　matrix.　Meanwhile,　a　biomass　additive　(PA@CS)　was　prepared　through　phytic　acid　(PA)　solution　as　the　grinding　medium　modifying　cellulose　(CS)　particles　by　the　ball　milling　process.　As　the　PBAT/10PLA/PA@CS　foam　presented,　PA@CS　implanted　into　pore　walls　which　supported　the　structure　integrity　of　foams　and　presented　the　lowest　surface　temperature　when　heating　at　170　°C　for　180　s.　The　compressive　strength　of　PBAT/10PLA/PA@CS　foam　with　5　wt%　of　PA@CS　addition　reached　1.05　MPa　at　20　%　strain.　During　the　combustion　process,　PA@CS,　as　flame　retardants,　demonstrated　excellent　suppressing　heat　dispassion　and　fire-resistance　performance.　For　instance,　5　wt%　of　PA@CS　presented　the　highest　ultimate　oxygen　index　(LOI)　(27.9　%),　and　UL-94　V-0　rating.　In　detail,　5　wt%　of　PA@CS　also　reduced　the　peak　of　heat　release　rate　(PHRR)　from　851.47　kW　m−2　to　524.45　kW　m−2　by　38　%,　total　heat　release　(THR)　from　84.34　MJ　m−2　to　66.45　MJ　m−2　by　21　%.　In　this　work,　PA@CS　as　an　efficient　biomass　flame　retardant　provided　technical　support　for　the　development　of　high-performance　compressive　strength,　thermal　insulation,　and　flame　retardancy　PBAT/PLA　foams.　©　2024　Kingfa　Scientific　and　Technological　Co.　Ltd.