Al-2at.% Nd alloy with a gradient cooling rate was prepared using a wedge-shaped mold in a vacuum environment. The relationship between gradient cooling behavior and the microstructure and properties of the Al-2at.% Nd alloy was investigated. The stability of the Al₁₁Nd₃ phase and the mechanical properties were confirmed through first-principles calculations. The results indicated that as the cooling rate decreased, the transformation of grain morphology in Al-2at.% Nd occurred as follows: a mixture of columnar grains and equiaxed grains→equiaxed grains. The grain size of the alloy increased. Discontinuous skeletal eutectic phases, α-Al and Al₁₁Nd₃, formed within the alloy, resulting in a reduction in the number of phase boundaries and grain boundaries. The hardness of the alloy decreased by 25.53%, and this pattern of change closely aligned with the calculated results.