Abstract: In combination with the actual situation of the secondary cooling of a billet continuous caster, a heat-transfer mathematical model was established with finite element software ANSYS. Heat-transfer coefficients in different secondary cooling regions were modified on the basis of pin-shooting results to improve the accuracy of the mathematical model. The results show that the modified mathematical model can simulate the whole heat-transfer and solidification process of the continuous caster. The location of electromagnetic stirring was determined by referencing the results of numerical simulation and pin-shooting techniques. Central carbon segregation and porosities in billets were alleviated by adopting electromagnetic stirring.