Abstract: Taking 70 t two-strand tundish of a steel plant as the prototype, the flow field characteristics of the twostrand tundish were studied with the method of physical simulation. Different parameters of flow control, such as weir depth, dam height, the distance between dam and weir, were set in the tundish. The optimized scheme was finally determined, by comparing the retention time distribution (RTD) curves of the fluid in the tundish under different flow control parameters. The results show that when the working surface height of tundish is 440 mm, the optimal process parameters of the tundish flow control are the weir depth of 80 mm, the dam height of 100 mm and the distance between dam and weir of 120 mm.