下法是根据“其实者,散而泻之”(见“素问·阴阳应象大论》)的原则来立法的。有关下法治疗疾病的论述首见于《内经》,《素问·热论篇》载:“其未满三日者,可汗而已,其满三日者,可泄而已)”,指出热病可用泄下而愈。张仲景《伤寒论》也颇注重下法,他所提出的治疗阳明腑实的大、小、调胃承气汤,都是排除燥实,清肃里热的方剂。金元时代张子和以擅用攻下著称于世。对火热病,刘河间运用下法治疗里热实证多有发挥,提出热毒极深采用承气汤与黄连解毒汤两方联合运用。明代是又可对温疫治疗主张“急症急攻”,尤推崇大黄之类的药物, The following method is based on the principle of “actually, scattered and diarrhea” (see “Principles of Yin, Yin and Yang should be like”). The discussion about the treatment of diseases under the first method is found in the “Inner Scripture”, “Su Wen·He Commentary: “The people who are less than three days old, but Khan only, and those who are full of three days, they can only vent it.”, pointed out that the fever can be leaked out. Zhang Zhongjing “Treatise on Febrile Diseases” also pays attention to the law, he The proposed treatment of Yangming’s large, small, tonifying Chengqi Decoction is a prescription that eliminates dryness, clearness, and heat. Zhang Zihe in the Jin-Yuan era was known for his offensive use. Inter-subjective use of the following methods to treat the fever has proved to be more effective, suggesting that the use of Chengqi Decoction and Huanglian Jiedu Decoction in combination with the use of the next method is extremely effective. The Ming Dynasty is also able to claim “emergency emergency attack” on the epidemic disease treatment, especially the promotion of rhubarb and the like. Drug,