Abstract: To investigate the effect of electromagnetic swirling flow in the nozzle（EMSFN）technology on the molten steel flow behavior in a slab continuous casting mold,a water model system with a geometric scaling ratio of 3∶1 was established based on similarity criteria,using a slab mold（1 450 mm×200 mm）as the prototype.A mechanical swirling rotor was installed inside the submerged entry nozzle to simulate the external field intervention effect of EMSFN.The influence of the nozzle swirling flow on the fluid flow pattern,liquid level fluctuation,and velocity distribution within the mold under different outlet flow rates of water model system was systematically studied.The results show that under conventional casting conditions,the flow field in the mold is asymmetrically distributed,with interfering upward flow occurring in the lower recirculation zone.The liquid level fluctuation intensified with increasing outlet flow rate,exceeding ±2 mm near the nozzle.After applying the nozzle swirling flow,the flow field symmetry was significantly improved.The impingement point of the nozzle outflow on the narrow face shifted upward,effectively dissipating the kinetic energy of the lower flow and suppressing the lower vortex,thereby stabilizing the liquid level fluctuation within ±1 mm.This study confirms that applying nozzle swirling flow enables effective control of the mold flow field,which provides a theoretical basis for the industrial application of EMSFN technology in slab continuous casting.