The invention is a mathematical modeling evaluation method for tundish flow control effect, comprising the following steps: adopting numerical technique to simulate and track the characteristic value of residence time distribution (RTD) curves of a tracer agent to evaluate the quality on the tundish packet type and a flow control device; establishing evaluation standard for RTD curve quality; the tundish flow control effect being better when dimensionless concentration at peak value of the RTD curve is more than 1, and the dimensionless time corresponding to the peak value is more than 0.75. The method provided in the invention is suitable for evaluating the quality of the tundish packet type and the flow control device, can evaluate the metallurgical effect of the tundish rapidly and effectively, and plays a leading role in optiming and revamping the tundish packet type and the flow control device in site. The method also can be applied to the analysis of water modeling experiment results.