Prewarming process in baking process of prebaked anode

Disclosed is a preheating method for a pre-baked anode baking process, an IP curve is made by the principle of in an anode baking and preheating phase with a 28h furnace-moving period and auto-controlled temperature and negative pressure, a corner furnace chamber and a non-corner furnace chamber respectively adopt different temperature curves, and temperature deviation and negative pressure limit value of an end flue are different from that of a middle flue. Moreover, when a baking system moves in the corner furnace chamber, a smoke discharging support directly moves on to the downstream furnace chamber communicated with the flues and stays for two flame-moving periods. The preheating method not only can sufficiently recycle volatile constituent combustion heat energy, but also can decrease energy consumption of anode baking by more than ten percent and extend holding time of anode baking by more than two hours.