The invention relates to silicon-solid-solubility high-strength plastic ferrite spheroidal cast iron, a manufacturing method and parts of rail locomotives, and belongs to the technical field of metallurgy. The spheroidal cast iron contains 3.0 percent to 3.2 percent of C, 3.8 percent to 4.1 percent of Si, less than 0.2 percent of Mn, less than 0.03 percent of P, less than 0.02 percent of S, 0.02 percent to 0.03 percent of Mg, the balance of Fe and other inevitable components; and C plus 1/3 Si is more than or equal to 4.3 percent and less than or equal to 4.7 percent, and Mn plus P plus S plusthe other inevitable components are less than or equal to 0.3. According to the silicon-solid-solubility high-strength plastic ferrite spheroidal cast iron, the manufacturing method and the parts ofrail locomotives disclosed by the invention, the yield strength Rp0.2 is increased by 33.4 percent to 44.7 percent, an elongation ratio is increased by 100 percent to 233 percent, and a no-gap impactvalue is increased by 25 percent; and therefore, graphitization is promoted, content of ferrite is increased, and the silicon-solid-solubility high-strength plastic ferrite spheroidal cast iron has the advantages of resource and cost.