<p>Ladle change is an essential stage to guarantee the continuity of casting, occurred periodically during tundish operations. At the beginning of a new ladle teeming, part of the liquid steel tends to be exposed to the atmosphere under the impact of the strong upward reverse flow, due to the low bath level and the high refilling flow rate. The present study proposed a novel multi-port turbulence inhibitor to remain a stable slag layer during unsteady tundish operations. A 1/3 scaled water model was established to investigate the multiphase flow in a five-strand tundish. It was found that the additional port area could reduce the initial velocity of liquid flowing out of the turbulence inhibitor. The reverse flow was split into several sub-streams by multi-port turbulence inhibitor, which dramatically enhances the momentum transport between the reserve flow and existing liquid in the pouring region. As liquid eddied within the chamber of turbulence inhibitor, the sub-streams flow out of the auxiliary ports obliquely, with less vertical velocity component. Owing to the multi-port turbulence inhibitor, the velocity of the reverse flow passing through the main port was 0.138 m/s, which is 43.0 pct lower than that in the tundish with conventional turbulence inhibitor. The global area of slag eye was reduced by 81.8 pct that can effectively inhibit the heat loss and reoxidation of liquid steel during unsteady tundish operations. The multi-port turbulence inhibitor is an appropriate approach to promote the cleanness of steel billet.</p>