Abstract: A mathematical model for thermal transmission and solidification of beam blanks was established,and it was discretized and solved by finite element method(FEM).A dynamic secondary cooling control model of beam blanks was developed on the basis of the mathematical model.The dynamic secondary cooling control model can dynamically calculate the entire real-time temperature field of beam blanks with a cycle of five seconds,set up and optimize the amount of water for second cooling by using virtual casting speed and target surface temperature.A dynamic secondary cooling control system of beam blanks was programmed by using Visual C++ 6.0.Under the same conditions of casting processes,the simulation result of the dynamic secondary cooling control system is in a good accordance with that produced by Marc software,indicating that the dynamic secondary cooling control system can be applied to online control or offline design and optimization for secondary cooling in beam blank continuous casting.