A new butterfly-like cluster, [WOS3Cu2(phen)2]·3H2O (1) (phen = 1,10-phenanthroline) has been synthesized and characterized by elemental analysis, infrared spectroscopy, ultraviolet-visible spectroscopy, X-ray single crystal analysis and fluorescent analysis. Its crystal structure is monoclinic with space group $C2/c$ and cell parameters: a = 31.928(6) Å, b = 10.653(2) Å, c = 23.097(5) Å, 𝛼 = 90°, 𝛽 = 133.11(3)°, 𝛾 = 90°, V = 5735(2) Å3, 𝑍 = 8. This complex displays a favourable pairwise 𝜋-𝜋 stacking. Density functional theory and time-dependent density functional theory calculations at the B3LYP/LanL2DZf+6-31G* level were performed on complex 1 to rationalize its experimental absorption spectra. Complex 1 exhibits luminescence in EtOH solution at room temperature.