<p>To address the clogging issue of the submerged entry nozzle (SEN) caused by the aggregation of Al₂O₃ inclusions during the continuous casting of ultra-low carbon interstitial-free (IF) steel, this study established a pulsed electric field system in an industrial continuous casting production line. The SEN was used as the positive electrode, and an Al₂O₃-C refractory rod in the tundish served as the negative electrode. The study systematically investigated the effects of combinations of current intensities (100/150&#xa0;A) and frequencies (10/40&#xa0;kHz) on the size distribution of Al₂O₃ inclusions. The action mechanism was revealed by combining analysis with an ASPEX automatic inclusion analyzer and observation of micro-morphologies. The results showed that, compared with the working condition without pulsed electric current (PEC), the application of PEC significantly optimized the characteristics of inclusions: The number density of inclusions decreased from 0.73 per mm² to a minimum of 0.57 per mm²; The proportion of small-sized inclusions (≤&#xa0;5&#xa0;<i>μ</i>m) increased from 70.30 to a maximum of 89&#xa0;pct; The proportion of large-sized inclusions (&gt;&#xa0;20&#xa0;<i>μ</i>m) could be reduced to 0. There was a synergistic effect between current intensity and frequency, with the combination of 150&#xa0;A and 40&#xa0;kHz achieving the optimal effect. Under this working condition, Al₂O₃ inclusions transformed from large dendritic clusters (observed when no current was applied) into isolated spherical/ellipsoidal particles smaller than 5&#xa0;<i>μ</i>m. Mechanism analysis indicated that current intensity enhanced the migration velocity of inclusions by increasing the electric field force, while high-frequency pulses inhibited the agglomeration of inclusions by inducing their high-frequency oscillation. This study provides an effective technical approach and theoretical support for the on-line prevention and control of SEN clogging during the continuous casting of ultra-low carbon IF steel.</p>