Abstract:The coarse bulk primary silicon structure, lathlike or needlelike eutectic silicon structure and αAl grains in the AlSi cast alloys seriously weaken the mechanical properties of the alloys. Currently there are many introductions on the research status of the modification of P, Sr, Na or single rare earth elements, but there is a lack of systemic summary of rare earth composite modification research. The paper systemically introduces the rare earth composite modification technology of AlSi cast alloys, and expounds the rare earth modification of primary silicon and eutectic silicon and the rare earth refinement mechanism of αAl grains, respectively, systematically introduces and summarizes the effects of rare earth composite modification of AlSi cast alloys on the microstructures such as primary silicon, eutectic silicon, αAl grains, as well as their compressive strength, elongation, wear rate, roughness, corrosion resistance among other properties, expounds the application status and market prospect of rare earth modification technology of AlSi cast alloys, and summarizes and gives an outlook of the rare earth modification technology of alloys.