Furnace core temperature is one of the important characterization of blast furnace hearth active degree. The heat transfer calculation equation of Shougang Jingtang No.1 blast furnace core is given as a one-dimensional steady-state heat transfer process. The furnace core temperature is studied by calculating and drawing the curves of the furnace core temperature - the hearth temperature and the furnace core temperature - ceramic pad thickness. The suitable furnace core temperature is 310-380℃ at the present stage. The hearth condition is difference and the correlation is weak between the furnace core temperature and the temperature of molten iron when the furnace core temperature is low.