<p>Large-section continuous casting round blooms are prone to center macrosegregation due to long-distance solute transport, leading to ultrasonic testing failures in rolled products. To investigate the influence of solidification end reduction on macrosegregation of round bloom, a three-dimensional solute transport and a thermal–mechanical coupling model was established to analyze the equivalent von Mises stress, equivalent plastic strain, fluid flow, and solute transport of round bloom blooms with the different reduction schemes. The data of the initial position of the reduction are imported into the thermo-mechanical model by Fortran from the solute transport model. After the calculation of the thermal–mechanical model is completed, the deformation characteristics are extracted to calculate the extrusion speed of the solidified shell to the two-phase region. It will be fed back to the three-dimensional solute transport and a thermal–mechanical coupling model to update the wall boundary conditions to reveal the improvement mechanism of reduction on the center segregation. The deformation law of the round bloom during the reduction process was studied by using the scheme of double concave roller staggered reduction at the end of solidification, and a method for determining the effective strain zone based on specific temperature was proposed. When pressed at a position with a large liquid fraction, the strain transfer efficiency is higher. In the same reduction interval, the larger the reduction, the greater the strain transmitted to the center of the round bloom. The deformation and solute transport of different reduction schemes were compared. The results show that for the 40Cr round bloom of φ600 section, when the reduction amount is 24 mm and the reduction interval is 0.45–1, the central segregation is reduced from 0.4421 to 0.428 pct, which significantly improves the central segregation defect.</p>