Xiao Cheng Qi Tang is characterized by its ability to lighten the heat knot. Xiao Cheng Qi Tang consists of three medicines: rhubarb, thick park, and hedgehog. It can lighten the heat knot. It is used to treat Yangming viscera solid light evidence. Phlegmatic language (babbling) hot flashes (a burst of fever), constipation, chest and abdomen plumpness (stomach distension and discomfort), old yellow tongue, slippery pulse and disease; or dysentery at the beginning of the abdominal distension, abdominal pain, after the weight (discomfort in the lower abdomen, would like to defecate, defecation after a sense of incompletion) people. In the formula, rhubarb has the effect of diarrhea and heat (removing heat and evil, dredging the bowels); thick park has the effect of moving qi to remove flatulence; hedgehog has the effect of eliminating plaques and dispersing knots, and the three medicines are combined to play a role in diarrhea and heat to remove the effect of flatulence. Xiao Cheng Qi Tang should be used correctly under the guidance of a professional physician, and people with a weak constitution should be cautious of using this drug to avoid the occurrence of loose stools, abdominal discomfort and other adverse reactions.