This　work　discusses　the　characterization　of　the　hot　cracking　resistance　and　mechanical　properties　of　Al-Cu-Mn-Cd　(-Er-Zr)　alloy　using　the　＂constrained　rod　casting＂　method　and　mechanical　tensile　testing.　Analysis　of　the　Al-Cu-Mn-Cd　(-Er-Zr)　alloy＇s　microstructure　was　conducted　using　testing　methods　such　as　optical　microscopy,　scanning　electron　microscopy,　transmission　electron　microscopy,　and　others.　The　results　indicate　that　alloys　with　the　addition　of　Er　and　Zr　exhibit　higher　resistance　to　hot　cracking　compared　to　alloys　without　Er　and　Zr.　The　Er　and　Zr　mainly　refine　the　grain　size　by　increasing　the　degree　of　ingredient　supercooling,　while　simultaneously　improving　the　alloy＇s　resistance　to　hot　cracking　by　increasing　the　proportion　of　eutectic　structure.　The　addition　of　Er　and　Zr　results　in　grain　size　refinement　and　a　reduction　in　the　secondary　dendrite　arm　spacing.　The　average　grain　sizes　of　alloys　containing　Er　and　Zr,　and　alloys　without　Er　and　Zr,　are　138.43　mu　m　and　151　mu　m,　respectively.　The　average　spacing　of　secondary　dendrite　arms　is　21　mu　m　and　31　mu　m,　respectively.　The　average　tensile　strengths　of　alloys　treated　with　T6　heat　treatment　are　500　MPa　and　474　MPa,　respectively.　During　the　heat　treatment　process　of　the　alloy　containing　Er　and　Zr,　the　formation　of　the　Al3(Er,　Zr)　phase　provides　non-uniform　nucleation　sites　for　the　theta　＇　phase,　thereby　reducing　the　size　of　the　theta　＇　phase　and　consequently　enhancing　the　strength　of　the　alloy.