<p>This paper explores the impact of Ti, Sr, and Mo on the microstructure, mechanical properties, and solidification behavior of ADC12 alloy. The results indicate that adding these elements can significantly refine the grain size of ADC12 alloy and alter the morphology of eutectic Si. In terms of mechanical properties, the addition of Ti and Sr can increase the alloy’s hardness, but excessive addition leads to a decrease in hardness. The electrical conductivity decreases with the addition of Ti and Mo, while the proper addition of Sr can improve it. Thermal analysis reveals that Ti, Sr, and Mo influence the nucleation and growth of α-Al and eutectic Si by altering the solidification path and phase transition temperature. The undercooling and nucleation rate of primary <i>α</i>-Al in the alloy with Ti addition see a significant increase. In the alloy with Sr addition, the nucleation temperature and growth temperature of eutectic Si decrease markedly, the undercooling of eutectic Si increases significantly, and the modification effect is optimal. Mo addition has the greatest influence on the nucleation temperature of eutectic Al₂Cu in the alloy.</p>