Balancing middle energizer is a general method for treating spleen and stomach diseases proposed by Wu Jutong，a doctor of the Qing Dynasty，based on the physiological characteristics of the spleen and stomach.Later doctors，on the basis of this method and clinical practices，created a theoretical system involving the etiology，pathogenesis，and treatment of spleen and stomach diseases with balancing middle energizer as the breakthrough point.Precancerous lesions of gastric cancer(PLGC) are a pathological state with a high risk of canceration.We explored the etiology and pathogenesis of PLGC from the theory of balancing middle energizer.Considering the physiological and pathological characteristics of the spleen and stomach，we believe that this disease is caused by multiple factors that cause continuous damage to the gastric mucosa.In the battle between pathogenic and healthy qi，the protection and defense mechanism of the gastric mucosa is activated，which disturbs the dynamic balance and leads to spleen-stomach deficiency，collateral damage due to stasis，and imbalance of ascending and descending，followed by pathological changes and clinical manifestations.Regulating various factors such as qi and blood，deficiency and excess，and qi movement by means of harmonizing the middle energizer can restore the balance of spleen and stomach and the normal ascending and descending of qi movement，thereby treating PLGC.