Abstract: Taking the eight-strand billet tundish of a steel mill as the research object, the physical and numerical simulation methods were used to evaluate the problem of steel flow in the tundish under the original flow control scheme based on parameters such as flow field, temperature field, and residence time distribution. The influence of the number, aperture, position, and inclination angle of diversion holes in the retaining wall on the flow characteristics of steel in the tundish was analyzed to optimize the flow control device in the tundish.The results show that under the original flow control scheme, there are problems with a large dead zone volume, poor consistency among different flows, and uneven temperature field in the ladle molten steel. The optimized flow control plan is to reduce the aperture of two diversion holes on the side wall of the retaining wall and increase their position, and to add small diversion holes with a deviation angle (43°) and an elevation angle (15°) on the middle wall.The flow field and temperature field in the tundish of the optimized scheme are significantly improved, with the dead zone volume ratio reduced from 19.04% in the prototype scheme to 7.06%. The volume ratio of piston flow and fully mixed flow has increased, and the consistency of the stagnation time, actual average residence time, and peak time of each strand is increased to over 80%, resulting in a significant improvement in the consistency among each strand. For the optimized scheme, the maximum temperature difference of the tundish is 16.004 K, which is 2.182 K lower than the prototype scheme, and the maximum temperature difference of liquid steel at the outlet of each strand is 0.616 K, which is a decrease of 0.944 K compared to the original plan, and the temperature field of the entire tundish is more uniform.