The invention discloses a center segregation control method for producing a 30CrMo circular tube steel casting blank with the cross section of phi280mm, belonging to the field of metallurgy. The method comprises the following steps: converter smelting, LF (ladle furnace) refining of molten steel, RH refining, continuous casting of molten steel and the like. The key technology is characterized in that a crystallizer electromagnetic stirring-final electromagnetic stirring combined technique is adopted in the continuous casting stage. The reasonable parameter control is performed in the molten steel smelting stage to enhance the purity of molten steel and achieve the optimal outbound conditions; in the molten steel casting process, the crystallizer electromagnetic stirring-final electromagnetic stirring combined mode is adopted, so that the molten steel components are uniformized; the casting is carried out at lower temperature, so that the blank shell grows uniformly; and thus, the columnar crystal structure is continuously eroded and blown out in the stirring process, the equiaxed grain nucleation rate is enhanced, and the columnar crystal growth is inhibited, thereby avoiding or reducing the center segregation of the casting blank.