For　three　different　purification　treatment　methods　of　aluminum　melt:　untreated　(UT),　conventional　purification　treatment　(CPT),　impurity　removal　flux　purification　treatment　(IRF),　and　Al-10Sr　intermediate　alloy　was　applied　for　modification　treatment.　The　results　showed　that　due　to　the　highest　purity　of　aluminum　liquid　treated　with　IRF,　the　secondary　dendrite　spacing　decreased　by　31.32%　after　modification,　and　the　eutectic　silicon　phase　was　in　a　granular　and　dispersed　distribution.　The　tensile　fracture　exhibited　ductile　fracture　characteristics,　effectively　improving　the　mechanical　properties　of　the　alloy.　At　the　same　time,　it　was　found　that　reducing　the　Sr　content　did　not　decrease　the　modifying　effect,　indicating　good　purity　of　aluminum　liquid　can　provide　superior　melt　conditions　for　subsequent　modification　treatment.　　©　Published　under　licence　by　IOP　Publishing　Ltd.