The invention provides a ductile iron casting, which comprises the following chemical components: 3.5-3.9% of C, 2.4-3.2% of Si, 0.4-0.5% of Mn, less than or equal to 0.1% of P, less than or equal to 0.03% of S, less than 0.04% of Ti, 0.030-0.045% of Mg residual, 0.005-0.015% of Re residual, and the balance Fe. The manufacturing method consists of: conducting inspection and compounding in front of a furnace, then carrying out smelting, nodularization, and then performing aftertreatment, like heat treatment, shot blasting, polishing and machining, etc., thus obtaining an output product. Twice inoculation achieves a good effect. The production process is simple, and has obviously decreased energy consumption, thus being suitable for mass production. While ensuring good comprehensive mechanical properties of ductile iron, the method saves adding of copper, tin and other precious metals. In addition, the ratio of raw materials is simple, and magnesium and rare earth are both controlled within the required range, so that the graphitization level of the ductile iron body molded by casting is stabilized at 1-2.