Under the guidance of Mr. QIN Bowei and academician DONG Jianhua, Professor DU Huaitang advocates the idea of unifying cold and heat in the diagnosis and treatment of exogenous fever diseases, while in the treatment of internal injuries and miscellaneous diseases, he adheres to the medication characteristics of Menghe school and moderating and makes good use of classical prescriptions in the treatment of exogenous and internal injuries. Chaihu Xianxiong Decoction (柴胡陷胸汤) is a commonly-used clinical prescription. This prescription is a reconciliation dredging and descending formula made by adding and subtracting Xiaochaihu Decoction (小柴胡汤) and Xiaoxianxiong Decoction (小陷胸汤) in ,Treatise on Febrile Diseases,. It also takes the advantages of Xiaochaihu Decoction in reconciling the exterior and interior and the function of Xiaoxianxiong Decoction in clearing heat and eliminating phlegm, supplemented by Zhishi (Fructus Aurantii Immaturus) and Jiegeng (Radix Platycodonis) to regulate Qi. Modern doctors often use this prescription to treat the diseases and syndromes of heart system, spleen and stomach system and Qi, blood and body fluid system. Professor DU often uses it as the basic prescription and apply it to treat fever, cough, vertigo and other Shaoyang diseases, which syndrome was phlegm Qi intersection and heat accumulation. It can play the role of reconciliation of Shaoyang and calming cold and heat, regulating Qi and resolving phlegm, calming vertigo, ascending and descending and stopping cough, reflecting the characteristics of "simultaneous treatment of different diseases" in traditional Chinese medicine. On the basis of the effect of this prescription, it is often combined with the drugs of nourishing Yin and nourishing blood, so as to prevent the excessive use of the drugs of clearing heat, resolving phlegm and regulating Qi from damaging the body fluid and blood, reflecting the meaning of "always taking care of the body fluid and blood", and the clinical effect is good, which provides some reference and inspiration for the clinical application of modern traditional Chinese medicine to expand the scope of application of this prescription and point out the application characteristics of this prescription.