The invention relates to an air flow control system and a control method, in particular to a tank type furnace air flow control system and a control method for producing anodes, cathodes, electrodes and carbon graphitization material for aluminum manufacturing in the carbon industry. The control system is structured in a manner that: a pressure sensor is arranged in a preheated air vertical channel, and sends a signal to a controller; the controller sends a control signal to a valve; the valve is connected with a preheated air horizontal channel through a reducing pipe; and the preheated air horizontal channel is communicated with the preheated air vertical channel. The openness of the valve in the air inlet position can be automatically adjusted according to the condition of negative pressure of air entering a flue so as to adjust the air flow; the complete combustion of volatile matters of every flue can be guaranteed; and what is important is that the excess air coefficient can be controlled, so that the cooling of a furnace due to excess air is prevented, and the total energy consumption of the furnace is reduced.