By means of heat conduction model of the cathode of aluminum electrolytic tank,the gas baking startup technology for electrolytic tank is investigated numerically. Under different baking processes, the change of heating speed, temperature difference in the cathode and heating load vs. time are studied.The baking time needed and fuel consumption under different baking processes are discusses, and the characteristics of baking processes are compured each other. The result reveal the best process to startup electrolytic tank; it provides theoretical reference to work out proper baking process for gas baking startup technology for aluminum electrolytic bath.