<p>Magnetic fields generated during electromagnetic braking in continuous casting mold may alter mold flux crystallization. In this study, the influence of a static magnetic field on the crystallization behavior of CaO–SiO₂-based mold flux was examined using the <b>S</b>ingle <b>H</b>ot <b>T</b>hermocouple <b>T</b>echnique combined with a static <b>M</b>agnetic <b>F</b>ield (<b>SHTT+MF</b>). Although the mold flux exhibits paramagnetic behavior, thermodynamic analysis demonstrates that the magnetic contribution to the Gibbs free energy is negligible compared with the chemical driving force for crystallization. Consistently, the initial crystallization temperature remains unchanged under a 30 mT magnetic field. In contrast, the crystallization kinetics are significantly affected. The incubation time decreases under magnetic field, advancing crystallization by approximately 10 to 20 seconds at a given temperature. Heterogeneous nucleation analysis reveals that this acceleration originates primarily from a magnetic field-induced reduction in contact angle without significantly altering interfacial energy magnitude. Crystal growth exhibits that at high temperatures, grain mobility is reduced due to transport damping, whereas at low temperatures, enhanced interfacial attachment facilitates growth under transport-limited conditions. Despite these kinetic effects, the crystallization mechanism is preserved and the apparent activation energy for crystal growth decreases from 636.33 to 497.74 kJ·mol⁻¹ under a 30 mT magnetic field.</p>