The invention belongs to the field of beverage fermentation, and particularly relates to a steel drum air pressure adjusting system and a method for beverage production. The steel drum air pressure adjusting system for beverage production comprises a fermentation tank, an air pressure sensor, a controller and a PH value sensor used for detecting the PH value of fermentation liquor, the fermentation tank comprises an inner bin and an outer bin, a cooling cavity is formed between the inner bin and the outer bin, the cooling cavity is communicated with a cooling pump, the fermentation tank is communicated with an exhaust bin, and a first valve is arranged at the air inlet end of the exhaust bin; a spring and a sliding block are arranged at the exhaust port end of the exhaust bin, the sliding block is fixedly connected with the inner wall of the exhaust bin through the spring, and a sliding piece used for controlling an exhaust port of the exhaust bin is arranged on the sliding block. According to the scheme, air pressure in the fermentation tank is monitored in real time through the air pressure sensor, different pressure adjusting modes are controlled through the PH value of fermentation liquor, the air pressure of the fermentation tank is stable, and the service life of the steel drum is prolonged; meanwhile, the PH value of fermentation liquor is stable, the storage and fermentation environment is intelligently regulated and controlled, the beverage production intelligence is improved, and the fruit wine quality is improved.