Abstract: In order to improve the flow field of T-shaped five-flow tundish and reduce the negative impact of the unsteady tundish changing process, the influence of increasing the pulling rate on the flow field distribution, the dead zone ratio and the residence time of molten steel in the tundish under steady conditions was studied through water simulation experiments, and the influences of the ladle flow and the ladle changing liquid level on the exposed liquid area and slag entrapment in the impact zone during the unsteady tundish changing process were analyzed. The results show that increasing the pulling rate is beneficial to improving the flow field in the tundish under steady state conditions, but it reduces the response time, peak time and residence time of the second flow outlet, which is prone to short-circuit flow and is not conducive to the full floating of inclusions. Therefore, considering comprehensively, the drawing rate of 0.58 m/min is appropriate. For the unsteady changing process, the higher changing liquid level and the lower ladle flow rate are conducive to the flow of molten steel in the ladle changing process. It is appropriate to comprehensively consider that the ladle changing liquid level is 400 mm and the ladle flow rate is 9 m³/h