Abstract: Base d on the measured data of "black box" experiment, the heat flux on the surface of steel plate was calculated by using the sequential function method, and the variation law of total heat exchange factor and furnace length of heat treatment furnace was obtained. According to the total heat exchange factor and heat transfer principle, the prediction model of steel plate temperature in No.6 heat treatment furnace of Nangang was established. The prediction results show that the maximum temperature difference between the predicted value of the model and the measured temperature is 13.34 ℃, and the average relative error of the model calculation is 0.92%. The results show that the model can be used to predict the temperature field of the steel plate, and it has a certain guiding role in actual production.