The macroscopic transport behavior inside the tundish simultaneously adopting electromagnetic weir and dam were investigated via a 3D computational fluid dynamics modeling. Results showed that the flow pattern of molten steel can be effectively controlled by local electromagnetic brake force to replace the conventional weir and dam made of refractory in the given tundish. The increases of magnetic intensities for both the electromagnetic weir and dam within the range of 0.05~0.35 T are conductive to the reduction of dead volume fraction and the increases of plug volume fraction and residence time of molten steel in the tundish. The recommended values of magnetic intensities in both the electromagnetic weir and dam zones are 0.3 T owing to that the changes for all RTD characteristics tend to moderate when further increasing the magnetic intensity. This work will provide a pertinent advice on designing electromagnetic weir and dam for the tundish to gain a desire flow pattern without physical flow control devices.