The　insulation　performance　of　power　equipment　is　compromised　by　the　aging　effects　of　various　physical　fields,　which　can　lead　to　failure.　This　study　investigates　the　impact　of　interface　modification　on　the　aging　behavior　of　composite　materials.　Polydopamine　(PDA)　is　employed　to　modify　the　surface　of　boron　nitride　nanosheets　(BNNS),　enhancing　their　compatibility　with　silicone　rubber　(SIR).　Thermal-mechanical　aging　tests　are　performed　to　compare　the　aging　properties　of　various　materials.　The　experimental　results　demonstrate　that　PDA-modified　BNNS　significantly　enhance　the　DC　electrical　and　mechanical　properties　of　BNNS/SIR　composites.　Additionally,　the　PDA-modified　BNNS/SIR　exhibits　superior　aging　resistance　under　thermal　aging　conditions.　Although　there　is　a　more　pronounced　decline　in　insulation　properties　under　thermal-mechanical　aging,　the　PDA-modified　BNNS/SIR　still　demonstrates　better　aging　resistance　compared　to　the　unmodified　BNNS/SIR.　This　study　provides　insight　into　developing　insulation　composites　with　excellent　aging　inhibition　characteristics.　©　2025　Society　of　Plastics　Engineers.