Isophorone　diisocyanate　(IPDI)　as　reactive　compatibilizer　was　introduced　into　poly(butylene　adipate　terephthalate)　(PBAT)/polylactic　acid　(PLA)　blend　by　melt　blending　and　extruded　into　blown　films.　The　effect　of　IPDI　content　on　the　phase　morphology,　crystallization　behavior,　mechanical,　thermal　and　barrier　properties　of　PBAT/PLA/　IPDI　blended　films　were　investigated　by　Fourier　transform　infrared　spectroscopy　(FT-IR),　scanning　electron　microscope　(SEM),　differential　scanning　calorimeter　(DSC),　universal　tensile　testing　machine,　thermogravimetric　analyzer　(TGA)　and　water　permeability　tester.　Results　demonstrate　that　the　—NCO　groups　of　IPDI　can　chemically　react　with　PBAT　and　PLA　to　form　copolymer,　which　reduces　the　particle　size　of　PLA　dispersed　phase　and　leads　to　indistinct　interface　between　the　two-phase,　effectively　improving　the　interfacial　compatibility　between　PBAT　and　PLA　matrix.　With　increasing　the　IPDI　content　in　PBAT/PLA/IPDI　films,　the　crystallization　ability　of　PBAT　matrix　and　tensile　strength　increase,　whilst　the　water　vapor　barrier　performance　increases　first　and　then　decreases.　When　the　mass　fraction　of　IPDI　is　0.5%,　compared　with　the　pristine　PBAT/PLA　film,　the　PBAT/PLA/IPDI　packaging　film　shows　74.2%　and　28.6%　enhancement　in　tensile　strength　on　the　transverse　direction　and　machine　direction,　respectively,　maintains　decent　breaking　elongation　of　790%　and　244%,　meanwhile,　38.2%　reduction　in　water　vapor　permeability　coefficient,　which　suggests　the　balanced　overall　mechanical　and　water　vapor　barrier　properties.　©　2023　Chengdu　University　of　Science　and　Technology.　All　rights　reserved.