In order 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 deeply studied, aiming to comprehensively improve the overall performance of the hypoeutectic Al-Si-Mg alloy. The results showed that Be delayed the decomposition of Mg2Si phase and promoted the transformation of π-AlSiMgFe phase to β-AlFeSi phase. The accelerated transformation of the morphology of the π-AlSiMgFe phase structure not only enhanced the strengthening effect, but also weakened the cleavage effect of the π-AlSiMgFe phase on the matrix, thus synchronously improving the strength and plasticity of the alloy.