Silicone　rubber　(SIR)　has　been　widely　used　in　the　insulation　of　cable　accessories　due　to　its　excellent　performance.　In　this　paper,　pure　SIR　and　nano　Al2O3/SIR　composites　are　thermally　aged　for　0-80　days　at　200°C.　The　effects　of　long-term　thermal　aging　on　the　space　charge　transport　are　analyzed.　The　results　show　that　with　the　increase　of　thermal　aging　time,　the　accumulation　of　heteropolar　charge　of　pure　SIR　and　nano　Al2O3/SIR　composites　gradually　decreases　and　changes　to　the　accumulation　of　homopolar　charge.　Compared　with　pure　SIR,　the　space　charge　accumulation　of　Al2O3/SIR　composites　decreases　significantly　and　changes　little　with　the　increase　of　thermal　aging　time.　It　is　believed　that　when　doped　nano　Al2O3　in　SIR,　the　increase　of　carrier　mobility　and　the　introduction　of　metal　oxides　reacting　with　fallen　free　radicals　to　form　stable　compounds　both　lead　to　less　space　charge　accumulation　of　Al2O3/SIR　composites.　©　2022　IEEE.