The　Al-Cu6.3-Mg1.3　alloy　with　high　Cu　content　was　designed　and　additively　manufactured　by　using　double　wires　and　arcs.　Key　findings　demonstrated　the　micro　hardness,　YS,　and　UTS　achieve　115.6　HV,　206　MPa,　and　307　MPa,　respectively.　Those　values　are　notably　increased　compared　with　that　of　the　WAAM　Al　alloys　with　traditional　compositions.　Dendritic　grains　dominate　the　microstructure　of　the　designed　alloy　with　Cu　and　Mg　contained　eutectic　structures.　The　in-situ　precipitated　and　homogeneously　distributed　nano-scale　needle-shape　metastable　S′　phases,　which　are　triggered　by　rapid　solidification　and　intrinsic　heat　treatment　during　WAAM,　contribute　to　the　mechanical　properties　improvement　of　directly　deposited　alloy.　This　study　provides　a　promising　guidance　for　the　development　of　additively　manufactured　components　with　excellent　performance.　©　2021　Elsevier　B.V.