The　radial　forging　strain-induced　melt　activation　(RFSIMA)　was　adopted　to　process　the　as-extruded　6063　aluminum　alloy.　The　influence　of　radial　forging　on　the　microstructure　of　as-extruded　6063　aluminum　alloy　was　investigated.　The　semi-solid　microstructural　evolution　generated　by　the　directly　semi-solid　isothermal　treatment,　and　initially　radial　forging　predeformation　followed　by　semi-solid　isothermal　treatment　was　analyzed.　The　results　indicate　that　the　compaction　degree　of　RF-deformed　6063　aluminum　alloy　microstructure　gradually　increases　as　the　area　reduction　increases.　However,　this　increasing　pattern　is　not　obvious　when　the　area　reduction　increases　from　70%　to　85%.　In　addition,　more　ideal　semi-solid　microstructure　can　be　obtained　through　RFSIMA　as　compared　with　the　directly　semi-solid　isothermal　treatment.