The　Al　sheet　used　for　pressure　can　manufacture　(or　called　Al　piece)　was　prepared　by　different　melt-treatment　techniques　and　using　the　lower　grade　commercial　purity　raw　Al　(A199.5).　And　the　influence　laws　of　melt-treatment　techniques　on　the　metallurgical　quality　and　mechanical　properties　of　Al　piece　were　investigated.　It　is　found　that　high-efficient　melt-treatment　technique　improves　the　metallurgical　quality　of　Al　piece　remarkably,　that　is,　the　rate　of　removing　inclusions　and　the　extent　of　lowering　porosity　amount　to　about　66.6%　and　87.0%,　respectively,　and　as-cast　mean　grain　diameter　decrease　to　a　great　extent,　and　the　coarse　and　long　needle/flake　Fe-rich　impurity　phases　transform　into　complex　compounds　of　tiny,　sphere/short　stick　form,　which　makes　fracture　mechanism　of　the　material　be　transformed　into　the　congregation　of　transgranular　micro-hole,　thus　raising　mechanical　properties　of　this　material　remarkably.　Its　metallurgical　quality　and　mechanical　properties　have　reached　or　exceeded　the　level　of　present　products.　It　is　feasible　that　Al　piece　is　made　by　using　the　lower　grade　commercial　purity　raw　Al.　The　viewpoint　that　the　purification　is　the　fundamental　and　key　process,　i.e.,　the　basic　of　modification　and　grain　refinement　processes,　has　been　also　further　tested　and　verified.