Abstract: This paper expounds Professor Li Guolie's academic thought and clinical experience in treating the halitosis of spleen and stomach damp-heat type based on the theory of "lightness removing excess". It is proposed that "lightness" has five meanings: light and clear medicinal properties, light dosage, concise compatibility, light decoction method and light treatment method; "excess" covers the syndromes of external and internal injuries, obstruction of qi mechanism and mixed deficiency and excess. The location of the halitosis of spleen and stomach damp-heat type is centered on the spleen and stomach in the middle energizer, involving the lungs, liver, and kidneys, with syndromes of mixed deficiency and excess; the core pathogenesis is the stagnation of qi mechanism in the middle energizer and the diffusion of damp-heat turbid evil in the triple energizers. The theory of "lightness removing excess" is used to guide the treatment of spleen and stomach diseases of damp-heat type, and the treatment principle of "triple energizers being divided and eliminated, and lightness being able to penetrate and reach the evil" is proposed. The upper energizer is promoted to activate the pivot of qi transformation, the middle energizer is adjusted to restore the mechanism of ascending and descending, and the lower energizer is penetrated to guide the turbid evil out. The self-made "Wuxiang Qingzhuo Yin" is used to gargle to quickly remove the turbid evil and symptoms, forming an internal and external coordinated diagnosis and treatment method of "light dosage to regulate the pivot, ingenious method to clear the obstruction", which provides new ideas and theoretical basis for the clinical diagnosis and treatment of spleen and stomach diseases of damp-heat type.