The invention discloses a rare earth aluminum-magnesium alloy tire mold casting material. Raw materials of the casting material include an aluminum-magnesium alloy, an aluminum-manganese alloy, a rare earth alloy and aluminum titanium boron. The aluminum-manganese alloy accounts for 0.03%-0.06% of the total mass of the aluminum-magnesium alloy, the rare earth alloy accounts for 0.01%-0.04% of the total mass of the aluminum-magnesium alloy, and the aluminum titanium boron accounts for 0.08%-0.12% of the total mass of the aluminum-magnesium alloy. The invention further provides a manufacturing method of a rare earth aluminum-magnesium alloy tire mold. The hardness, the machining performance and the mechanical performance of the tire mold manufactured by reasonably selecting low-pressure casting technology parameters are effectively improved, various index requirements for a hook face of the high-end radial tire segmented mold manufactured finally are effectively met, meanwhile the life of the mold in the best use state is prolonged, and the rare earth aluminum magnesium alloy tire mold casting material and the manufacturing method of the rare earth aluminum magnesium alloy tire mold become the historic promotion and progress again for low-pressure precise casting tire mold pattern block materials and preparing methods.