Conceptually　mimicking　biomolecules’　ability　to　construct　multiple-helical　aggregates　with　emergent　properties　and　functions　remains　a　long-standing　challenge.　Here　we　report　an　atom-precise　18-copper　nanocluster　(NC),　Cu18H(PET)14(TPP)6(NCS)3　(Cu18H)　which　contains　a　pseudo　D3-symmetrical　triple-helical　Cu15　core.　Structurally,　Cu18H　may　be　also　viewed　as　sandwich　type　of　sulfur-bridged　chiral　copper　cluster　units　[Cu6−Cu6−Cu6],　endowing　three-layered　3D　chirality.　More　importantly,　the　chiral　NCs　are　aggregated　into　an　infinite　double-stranded　helix　supported　by　intra-strand　homonuclear　C−H⋅⋅⋅H−C　dihydrogen　contacts　and　inter-strand　C−H/π　and　C−H/S　interactions.　The　unique　multi-layered　3D　chirality　and　the　double-helical　assembly　of　Cu18H　are　evocative　of　DNA.　Moreover,　the　collective　behaviours　of　the　aggregated　NCs　not　only　exhibit　crystallization-induced　emission　enhancement　(CIEE)　and　aggregation-induced　emission　enhancement　(AIEE)　effects　in　the　deep-red　region,　but　also　efficiently　catalyze　electron　transfer　(ET)　reaction.　This　study　thus　presents　that　hierarchical　assemblies　of　atomically　defined　copper　NCs　could　be　intricate　as　observed　for　important　biomolecules　like　DNA　with　emergent　properties　arising　from　aggregated　behaviours.　©　2023　Wiley-VCH　GmbH.