Abstract: Convection heat transfer coefficient and equivalent radial thermal conductivity are discussed, which have great effect on heat transfer in a HPH furnace. Using the approach of mathematical modeling, the convection heat transfer coefficient on each surface of a coil are studied for the complete cycle of annealing. In view of the analysis of thermal resistances, the equivalent radial thermal conductivity is investigated for different temperatures, compressive stresses, and atmosphere gases, respectively. It is shown that the HPH technique can significantly enhance the heat transfer compared with the traditional HHX method.