In order to make full use of the waste heat of electric arc furnace flue gas to preheat scrap, a three-dimensional unsteady random distribution local model of scrap preheating process was established on the platform of computational fluid dynamics software FLUENT. The temperature distribution law of different kinds of scrap in the shaft was explored by numerical simulation. The simulation results show that the preheating temperature of scrap increases obviously with the increase of preheating time, but the temperature rise rate decreases gradually; Under the same preheating conditions, the average temperature of light and thin scrap is about 1600 K, medium and heavy scrap is about 1000 K and heavy scrap is about 700 K; Increasing the specific surface area can improve the preheating temperature of various types of scrap to a certain extent. Considering the impact of scrap melting on smelting quality during preheating, the specific surface area of bottom scrap should be controlled below 1.5 m2 / m3. At the same time, in order to improve the preheating effect of heavy scrap, the specific surface area should be controlled above 0.25 m2 / m3; High temperature flue gas will preferentially pass through the area with good porosity, and the flue gas velocity in the densely stacked plate scrap area is small, so as to reduce its preheating temperature.