This paper presents studies of aeroelastic optimization on composite skins of large aircraft wings subject to aeroelastic constraints and strength/strain constraints. The design variable for optimization was the ply thickness of the wing skin panels, and the structural weight was the objective function to be minimised. The impacts of three strength/strain constraints and the ply proportion of the wing skin panels on the optimization results are discussed. The results indicate that the optimal composite wings that satisfy different constraints have remarkable weight advantages over metal wing. High levels of stiffness can be achieved while satisfying the constraints regarding allowable design strains and failure criteria. The optimization results with variable-proportions indicate that wing skins with higher proportions of 0° plies from the root to the middle segment and ±45° plies outboard have a more efficient and reasonable stiffness distribution. This paper presents studies of aeroelastic optimization on composite skins of large aircraft wings subject to aeroelastic constraints and strength / strain constraints. The design variable for optimization was the ply thickness of the wing skin panels, and the structural weight was the objective function to be minimized The impacts of three strength / strain constraints and the ply proportion of the wing skin panels on the optimization results are discussed. The results that that optimal composite wings that satisfy different constraints have remarkable weight advantages over metal wing. High levels of stiffness can The achieved results with variable-proportions indicate that wing skins with higher proportions of 0 ° plies from the root to the middle segment and ± 45 ° plies outboard have a more efficient and reasonable stiffness distribution.