The invention discloses a casting process for high-strength and low-alloy chilling spheroidal graphite cast iron camshaft blanks. The casting process is characterized by including the following steps that a, camshaft shells are manufactured according to the specification; b, iron boxes are manufactured, the shells manufactured in the step a are placed in the iron boxes, each iron box contains 4 to 6 shells, and gaps are formed between each shell and the inner wall of the adjacent iron box and between the shells respectively; c, the gaps are filled with iron pills, the shells are completely covered, and casting ports of the shells are exposed outside so that molten iron can be cast conveniently; d, the molten iron is cast through the casting ports, cavities of the shells are filled with the molten iron, and casting operation is finished; and e, the temperature is kept for 3 to 5 hours, the iron pills in the iron boxes are removed, camshaft castings are taken out, and therefore the camshaft blanks are obtained. By the adoption of the casting process for the camshaft blanks, the stress of the camshaft blanks can be eliminated, the thermal treatment process can be omitted, and the process is simple.