To investigate the effect of Be on the transformation of Fe-containing phases during solution treatment, a series of experiments combining Be with different solution treatment processes were designed, and the intrinsic relationship between its effect on the morphology of eutectic silicon and Fe-containing phases and the mechanical properties was studied, aiming to improve the overall performance of the hypoeutectic Al-Si-Mg alloy. The results show that Be delays the decomposition of Mg₂Si phase and promotes the transformation of π-AlSiMgFe phase to β-AlFeSi phase. The accelerated transformation of the structure and morphology of π-AlSiMgFe phase not only enhances the strengthening effect, but also weakens the cleavage effect of π-AlSiMgFe phase on the matrix, thus synchronously improving the strength and plasticity of the alloy.