The　radial　forging　combined　with　unidirectional　compression　recrystallization　and　partial　melt　(RFCUC-RAP)　and　radial　forging　combined　with　multi-axial　compression　recrystallization　and　partial　melt　(RFCMC-RAP)　were　proposed　to　prepare　6063　Al　alloy　semi-solid　billet.　The　microstructural　evolutions　of　semi-solid　6063　Al　alloy　prepared　by　direct　semi-solid　isothermal　treatment　(SSIT),　RFCUC-RAP　and　RFCMC-RAP　were　investigated.　Results　show　that　the　solid　grains　of　semi-solid　billet　prepared　by　direct　SSIT　are　large.　However,　solid　grains　of　semi-solid　billet　prepared　by　RFCUC-RAP　and　RFCMC-RAP　are　fine　and　spherical.　Additionally,　the　RFCUC-RAP　is　superior　to　the　RFCMC-RAP　owing　to　the　relatively　simple　deformation　process,　which　is　an　effective　method　to　prepare　high-quality　semi-solid　billet.