Abstract: From the perspective of the nature, taste and function of herbal medicines, the author explored the law of action of cold-heat combination medicines based on the understanding of the famous cold-heat combination formula and personal clinical practice experience. It is pointed out that the combination of cold and heat can harmonize cold and heat by using its nature, treating cold and heat mismatch; the main use of its taste can mediate the qi flow, strengthen yin and moisten dryness, treating imbalance of qi flow in the gastrointestinal tract and damp heat in the lower jiao, injuring yin and dry heat; the use of the nature of the two can help to remove evil, support the evil, harmonize the disease and harmonize yin and yang, treating deficiency and reality, evil but not deficiency, and water and fire imbalance of yin and yang. The use of cold and hot medicines together is known as the use of cold and heat. This article discusses the law of using cold and heat together based on the author’s understanding and experience of using ancient famous prescriptions for cold and heat. 1, the main use of its nature, can reconcile cold and heat, the treatment of cold and heat mismatch. According to the theory of Chinese herbal medicine’s nature and flavor and its attribution to the meridians and the basic principle of “treating cold with hot medicine and treating heat with cold medicine”, the cold medicine that can enter the meridian where the hot evil is located and the hot medicine where the cold evil is located are chosen to correct the cold and hot bias of the lesion by using the cold and hot bias of the medicine, which has the effect of reconciling cold and heat and can be used to treat the upper hot and lower cold, upper cold and lower hot, and the upper cold and lower hot, It can be used for the treatment of cold-heat mismatches such as upper heat, lower cold, upper cold, lower heat, upper cold, inner heat, upper heat, inner cold, liver (bile) heat, spleen cold, stomach heat, intestine cold, water drink, heat, etc. For example, if the lung swelling is caused by kidney Yang deficiency and phlegm-heat blocking the lung, the upper part of the lung swelling is characterized by coughing and asthma, spitting yellow phlegm, and the lower part of the lung swelling is characterized by edema of the shins and cold extremities. The former is cold and enters the lung to clear its heat, while the latter is hot and enters the kidney to warm its yang and disperse its cold, so that cold and heat can be used together to clear the upper and warm the lower, and then with Ephedra, Semen, Poria and Atractylodes to suit the condition. Lung distension, cough and asthma and hot lung evidence, the upper see cough and asthma, spitting sputum thin amount, the lower see small urine short red, dripping and astringent pain, dry stool, is the upper cold and lower heat evidence, often use the pungent hot dry ginger with half summer, ephedra, pungent, etc. to warm the lung to drink, promote the lung to fix asthma, and use cold medicine such as mouton, gardenia, quai mai and rhubarb to clear the lower jiao damp heat, the upper and lower take into account, then can be removed both cold and heat. Zhongjing used Radix laxative to treat the hot gangrene with vicious cold and sweating, which belongs to table cold and heat inside. The formula uses the bitter cold scutellaria and rhubarb impregnated with hemp boiling soup to clear the heat inside and remove the gangrene, and uses the pungent hot Radix laxative to decoct another juice to support Yang and fix the table. In the early years of the grassroots, I treated children with measles, I saw a dark red rash, the rash was not transparent, the face was clear and white, and I also saw clear and dilute diarrhea, which is a deficiency of Yang in the body, but also feel the wind-heat plague gas of the surface heat and cold inside the evidence, I used the cold nature of honeysuckle, forsythia with asclepias, geranium, red peony, etc. to clear the heat and detoxify the rash, and use the pungent fenugreek, dried ginger with licorice, etc., into the spleen and kidney to return Yang and rescue the rebellion, the results are quite rapid. The treatment of liver (gallbladder) heat and spleen cold with Chai Hu, Gui Zhi and Gan Jiang Tang, the treatment of stomach heat and intestinal cold with Wu Mei Wan, and the treatment of watery drink and heat with Xiao Qing Long and Shi Fu Tang are omitted. 2. The main use of its taste can mediate the qi flow, strengthen yin and moisten dryness, and treat the evidence of imbalance of qi flow in the intestines and stomach and the evidence of dampness and heat in the lower jiao injuring yin and dryness and heat. 2.1 Mediating the qi mechanism to treat imbalance of the gastrointestinal qi mechanism: bitter medicines have the effects of clearing, lowering, venting, drying dampness and strengthening yin respectively. Pungent herbs often have the effects of dispersing, opening up the knots and passing qi and blood, and in special cases, some pungent herbs can also moisten dryness. In terms of the range of cold and heat, the combination of bitter-cold and bitter-heat medicines is mostly used to mediate the qi flow, which is more comprehensive than the single horizontal draining, and is mostly used for gastrointestinal diseases such as fullness, pain in the abdomen and diarrhea, where the qi flow is out of balance. The commonly used clinical formulas such as Hanxia Diarrhea Heart Soup, Ginger Diarrhea Heart Soup, Licorice Diarrhea Heart Soup and Hovenia Anti-Plumping Pill are all famous formulas that use both cold and heat, with bitterness descending and pungency opening. The combination of bitter-cold Scutellaria with pungent-heat Dry Ginger is to take the bitterness of Scutellaria to lower the cold and clear the stomach to remove heat, and the pungency of Dry Ginger to open the knots and remove the lumps. The bitterness of scutellaria with dry ginger is a bitter drainage and dry dampness, and the pungent heat of dry ginger can invigorate the yang, pungent dispersion of dampness, so that the dampness and heat are divided. The author treats chronic colitis, the symptoms of abdominal pain, intestinal diarrhea, pain after diarrhea, anal discomfort, yellow tongue coating, damp-heat is more prevalent but the deficiency is not obvious, often in the study of Yin Huihe teacher cleanse the intestinal formula (scutellaria baicalensis, Huang Lian, red peony, septoria, peach kernel, winter melon seeds) on the basis of the addition of dry ginger, red vine, cold and heat to enhance the effectiveness of treatment. Zuo Jin Wan is to use a small amount of Wu Yu to dispel liver stagnation and rely on it to induce, so that Huang Lian can bitterly drain liver fire and stomach heat, inhibit the arbitrariness of liver qi, and receive the effect of suppressing liver and controlling acid to calm the stomach. The author in the treatment of damp heat phlegm fire depression with Yue Ju Wan, often combined with gardenia dry ginger soup, can obviously enhance the bitter pungent drainage of depression heat, disperse dampness and remove gangrene role. 2.2 Bitter, firm, pungent and moist, treating dampness and heat in the lower jiao and injuring yin and dry heat. Bitter-cold herbs, such as Zhi Mu, Huang Bai and Huang Lian, can directly fold evil heat and preserve yin and fluids, which is called bitter and firm. As qi arrives at the point where fluid also arrives, the pungent herbs such as dry ginger and cinnamon in the hot herbs can pass through qi and blood and spread fluid to moisten dryness, which is known as spreading fluid and moistening dryness. The use of cold medicine with bitter and firm effect and hot medicine with the effect of distributing and moistening dryness, bitter and firm, pungent and moistening, is often used in the lower jiao damp-heat accumulation, fluid can not be spread liver and kidney yin deficiency dry heat evidence. It is often used in the clinical treatment of middle and late stage diabetes mellitus complicated by neuritis, with thin legs and feet, soreness and weakness of the waist and knees, weakness of the gait, red tongue with little coating and weak pulse. It is a good way to prevent the bitter cold of the kidney from hurting the stomach, but it can also open up the airway and spread the fluids, so that the essence of the formula, such as tortoise, reed, angelica and many other nourishing medicines for the liver and kidney, can be spread to moisten the tendons and bones. The formula is also used for the treatment of discomfort in urination caused by prostatitis, or even retention of urine, which belongs to the lower jiao damp-heat and stasis, and is often used with Angelica Sinensis and Bitter Ginseng Pills, Coix Seeds and Fructus Fructus, together with Zhi Kidney Tong Guan Pills, to clear heat and remove dampness, resolve phlegm and move stasis, in which Zhi Cai and Bitter Ginseng dry dampness and clear heat to strengthen yin, accompanied by Fructus Fructus, so that the cinnamon, pungent to disperse dampness, moisten dryness and help Qi transformation. 3, the nature of the use of each other, can support the righteousness and dispel evil, to turn the disease evil, to harmonize yin and yang, the treatment of deficiency and reality witnessed by each other, the evil is real but the righteousness is not deficient and water and fire yin and yang imbalance evidence. In terms of the scope of using cold and heat, the nature of cold herbs is taken to clear heat and dispel evil, and the nature of heat herbs is taken to promote yang and help righteousness, so that the nature and use of each other are not only applicable to the mutual witness of deficiency and actuality, but also can be used for those with actual evil but not yet deficient, which has the effect of invigorating yang energy and promoting evil to go out. 3.1 Support the righteousness and dispel the evil, treatment of deficiency and reality: whether it is external fever or internal injury, while using cold medicine to clear the evil heat, you can use hot medicine as appropriate, especially hot medicine with the effect of helping Yang, such as Radix et Rhizoma, cinnamon, dry ginger. This can not only clear the heat to dispel the evil, but also warm the yang to support the righteousness, which is applicable to the deficiency of evil and deficiency of the deficiency of mutual witness. For example, if a person with a deficiency of Yang in the body suffers from a warm disease, the evil enters the heart camp, the mind is sometimes bright and sometimes obscure, the rash is faint, the tongue is red and less mossy, the pulse is weak, the positive energy is not supported, and the evil energy cannot reach outside, there is a danger of deficiency, when using rhinoceros (buffalo horn substitute) Lian Dong Di, Dan Xuan Yin Qiao and Zhi Bao Dan, etc. to clear the camp and penetrate heat, open the orifice and wake up the mind, often adding Radix et Rhizoma Ginseng, cold and heat together to support the righteousness and eliminate evil, can promote the evil heat S drug potential and reach outside. In the treatment of chronic renal failure combined with chronic heart failure, which is due to the deficiency of spleen and kidney yang and turbidity on the heart and lung, the cold medicines such as Radix et Rhizoma Pseudostellariae, Cinnamomum cassiae, Morinda Citrifoliae and Zelenia were used together with Ginseng, Radix et Rhizoma Lingzhi, etc. to benefit qi and water, warm yang and lower turbidity, with satisfactory results. 3.2 To toleration of the evil, treating the evidence of actual evil but not yet deficient: toleration [2] means to supplement and toleration of the righteousness to dissolve the evil and make it reach outside. In terms of the scope of the use of cold and heat, the nature of the use of each other, the use of different types of each other, has the effect of accelerating the outward flow of evil. The subtle difference between tonifying and helping to dispel evil is that it is not only applicable to the evidence of positive deficiency, but can also be used for the actual evidence where the positive qi is not yet deficient. For example, when using bitter-cold medicine to clear heat and dispel dampness, it is supplemented with small doses of pungent-heat medicine such as dried ginger, cinnamon and wu yu, which not only combine bitter and pungent to dispel dampness but also invigorate yang energy, like the warmth of the sun, so that the haze can be easily dispersed, which not only does not help heat but also has a complementary effect on the main medicine to clear heat and dispel dampness. For example, in the treatment of jaundice, not only is the use of Yin Chen Jie Fu Tang to treat Yin Huang a combination of cold and heat, different types of each other, even in the treatment of Yang Huang, the use of Yin Chen, Huang Bai, Gardenia and other clearing heat and dampness to remove yellow, while adding a small amount of dry ginger or Wu Yu and other pungent heat medicine as appropriate, not only can prevent cold injury to the stomach, but also pungent to disperse dampness and smooth the qi flow, speeding up the elimination of jaundice, especially for those who also have stomach and stomach fullness and yellow slippery coating. 3.3 To harmonize yin and yang and treat the disorder of yin and yang of water and fire: cold medicine is yin and hot medicine is yang, according to the theory of mutual use of yin and yang, the use of cold and hot has the function of harmonizing yin and yang and is used for the disorder of yin and yang of water and fire. For example, the “Bureau formula” black tin dan is a famous formula for treating the deficiency of true yang, cold from within, the prevailing cold forcing yang on top, the upper real and lower deficiency, the formula uses the sweet cold quality of black tin to nourish yin, subdue the floating yang, subdue the rebellion and calm asthma, and the sour hot sulphur yellow to nourish yang, the two drugs must be used together as the ruler, with the effect of reconciling yin and yang, water and fire and tonic, the effect of both the symptoms and the root cause. In the famous formula for treating paralysis, Gui Zhi Shao Yao Zhi Mu Tang, while using hemp, Fang and other dispelling medicines to eliminate wind and dampness, also uses pungent and hot Radix et Rhizoma Paeoniae with Gui Zhi to move Yang, warming the menstruation and dispersing cold to relieve pain, and uses sweet and sour cold Paeoniae and Zhi Mu to clear heat and nourish Yin, so that the combination of cold and heat can harmonize Ying and Wei and harmonize Yin and Yang. The formula uses Huang Lian to clear the heart fire and cinnamon to help the qi to flow the water from the kidney to the heart. Although the medicine is only two flavors, the difference between cold and heat is great, but it has the function of transporting the heart and kidney and harmonizing the yin and yang of water and fire.