The microstructure evolution and mechanical properties of Al–3.92Cu–1.10Li–0.68Mg–0.32Ag–0.23Mn–0.35Zn–0.11Zrand Al–3.92Cu–1.12Li–0.76Mg–0.29Ag–0.24Mn–0.24Zn–0.12Zr–0.083Sc (wt%) alloys during homogenization with differentcooling modes were comprehensively studied. It was clearly revealed that the minor Sc addition refined the grainsof as-cast Al–Cu–Li–Mg alloys through the formation of primary Al3(Sc, Zr) phases during the solidification process, andinduced Sc enrichment in the θ (Al2Cu) eutectic. After the homogenization treatment, the majority of coarse nonequilibriumeutectic phases at the grain boundaries dissolved into the α-Al matrix, leading to the relatively uniform distribution ofeach element. Sc-added alloy after homogenization treatments possessed more superior strength and ductility than Sc-freealloy. Compared to the furnace cooling mode, the air cooling mode could inhibit the precipitation of micron-sized coarse T1(Al2CuLi) phase and improve the mechanical properties of the alloys. After homogenization, the continuous Al2Cuphase inthe as-cast Sc-added alloy dissolved and transformed to an array of W-(Al, Cu, Sc) ternary phase, which was identified asAl6Cu6Scwith the body-centered tetragonal structure. The appearance of spherical Al6Cu6Scparticle could not damage themechanical properties of Al–Cu–Li–Mg alloys after the homogenization treatment. The tensile strength, yield strength andelongation of Sc-added alloy after the homogenization by air cooling were 390 MPa, 265 MPa and 10.8%, respectively. Theinvestigation of Al6Cu6Scphase offered a potential avenue to produce high-quality Sc-added 2xxx series alloys.