Abstract: Based on the analysis of controlled characteristics of the dynamic process of reheating furnace, the mathematical model, fuzzy control theory and fuzzy optimization are used to investigate the dynamic process, temperature optimization and control of reheating furnace. A fuzzy model is developed to optimize the furnace temperature available to hold for rolling and an on-line fuzzy control decision system is set up on the basis of slab's heat conduction mechanism model. Then, a furnace temperature control decision can be made for typical temperature holding process for further rolling by numerical simulation. The results show that the temperature of slabs in furnace can thus be controlled satisfactorily and the model developed is proved effectively for reheating furnace control system.