As　bone　repairation　biomaterial,　polycaprolactone　has　disadvantages　of　poor　mechanical　properties,　long　degradation　time,　hydrophobic　surface　and　poor　osteoinductive　property.　Mg　micro-particles　were　incorporated　into　the　PCL　matrix　to　produce　Mg/PCL　composite　materials　and　fused　extrusion　additive　manufacture　technology　was　used　to　fabricate　bone　repair　porous　scaffolds.　By　the　vitro　degradation　experiment,　from　the　pH　of　the　degradation　solutions,　the　result　shows　that　the　pH　of　Mg　/　PCL　increases　and　the　pH　of　pure　PCL　decreases,　which　indicates　the　degradation　of　the　composite　and　alkaline　substances　were　produced.　From　the　crystallinity　and　compressive　strength　test　results,　it　can　be　seen　that　the　addition　of　Mg　particles　reduces　the　crystallinity　and　compressive　strength　of　pure　PCL.　By　observing　the　micro　morphologies　of　porous　scaffolds,　Mg　particles　attached　to　the　surface　of　Mg　/　PCL　porous　scaffolds　gradually　fall　off　with　the　increase　of　degradation　time,　and　more　obvious　degradation　cracks　are　formed　on　the　surface　of　scaffolds.　The　molecular　weight　of　the　two　materials　after　degradation　was　measured.　The　molecular　weight　of　Mg/PCL　composite　decreases　more　obviously.　The　results　show　that　the　addition　of　Mg　particles　accelerates　the　degradation　rate　of　PCL,　and　the　Mg　ions　produced　by　degradation　promote　the　repair　of　bone　defects.　The　experimental　results　show　that　compared　with　other　biomaterials,　changing　the　content　of　Mg　in　composite　implants　can　regulate　the　degradation　rate　of　PCL　and　match　the　degradation　process　with　the　bone　regeneration　process,　which　has　good　application　prospects　in　the　field　of　osteochondral.　©　2021,　Editorial　Board　of　Polymer　Materials　Science　&　Engineering.　All　right　reserved.