Continuous casting method for improving carbon segregation of spring steel rectangular blank

The invention relates to a continuous casting method for improving carbon segregation of a rectangular spring steel blank, which comprises the following steps: accurately controlling the casting temperature and temperature gradient of ladle and middle ladle molten steel, the pulling speed, the crystallizer water quantity, the secondary cooling water quantity, the crystallizer electromagnetic stirring intensity, the tail end electromagnetic stirring intensity and the soft reduction in the continuous casting process to obtain ideal carbon segregation index and section carbon range; in the production process of rectangular billet spring steel, crystallizer steel passing amount, copper pipe inner wall quality, crystallizer water seam gap, crystallizer liquid level fluctuation amplitude, working condition of each secondary cooling section, nozzle working condition of each secondary cooling section, nozzle and spraying support centering, tundish molten steel superheat degree determination, defective billet cutting