Abstract: By the means of numerical model, the optimization of the geometrical parameters of slab continuous casting tundish configuration of the No. 3 Steel Plant in Taiyuan Iron and Steel Group were simulated. There are three evaluating indicators on time, one of which is the average time of stay of molten steel in the tundish. These indicators can be got by the impulse response experiment of the virtual tracer. The design of the total factor (four factors and tow levels) experiment is based on L₁₆(2¹⁵) orthogonal list. And the results ascertain the significant influencing factors by variance analysis and F test. The best working condition due to the three evaluating indicators is:the distance of retaining wall to the center line of water gap is 500 mm, the bottom of retaining wall to the bottom of tundish 200 mm, the center line of retaining wall to the center line of dam 322 mm, and the height of the dam 272 mm. It means that the flow behavior in the existed tundish is normal. But it will be better under the optimized condition. The disabled zone will be reduced from 4.80% to 4.37%. The disabled zone will be decreased by 2.53% if the turbulence inhibitor is used.