Abstract: Flow field of the two-strand slab caster's 80 t tundish equipped with flow control devices in a certain domestic steel plant was studied.Based on this research,the effects of position and height of tundish dam on flow field were tested and analyzed.It is concluded that with a double-deck turbulence controller,the flow field of the tundish was the most reasonable when the dam of 400 mm is installed 2 000 mm away from long nozzle;the structure of the flow control device consisting of turbulence controller and dam is so simple that it can protect molten steel from being polluted by its scouring to the dam or other tundish devices.Compared with previous tundish,the average residence time of fluid is increased from 292 s to 380 s,dead area ratio decreased from 37.3% to 18.5%,and ratio of piston area to dead area increased from 0.35 to 0.65,which is beneficial to uniformize steel temperature and composition,maximize inclusion floating and removal and improve cleanness of slab.