Abstract： Objective： To investigate the medication rules of YAO Xinmiao in the treatment of bi syndrome. Methods： Clinical data were collected from 505 bi syndrome patients who were admitted to YAO Xinmiao's expert clinic in The Third Affiliated Hospital of Zhejiang Chinese Medical University from January 2020 to September 2021，and the case data database was established using Excel 2013. Based on the Ancient and Modern Medical Records Cloud Platform (V2.3.5)， the data were normalized and data analysis such as frequency of medication， properties and clustering were performed. Results： A total of 505 patients involved 255 kinds of Chinese medicinals， from the frequency of use， YAO Xinmiao used Glycyrrhizae Radix et Rhizoma，Zingiberis Rhizoma Recens，Cinnamomi Ramulus，Paeoniae Radix Alba， Achyranthis Bidentatae Radix， Jujubae Fructus， Bupleuri Radix， Scutellariae Radix， Poria， Atractylodis Macrocephalae Rhizoma， Pinelliae Rhizoma Praeparatum Cum Zingibere et Alumine， Angelicae Sinensis Radix and other Chinese medicinals to treat bi syndrome. The main effects were to harmonize ying and wei， warm and activate meridians， relieve spasm and pain and so on. From the frequency of drug properties and the frequency of meridian tropism， the drug properties were mainly warm and balanced. Medicinal flavors overe mainly sweet，pungent and bitter. The main meridian tropisms were spleen，liver， kidney and stomach. Conclusion：YAO Xinmiao treated bi syndrome with the method of harmonizing ying and pathogen. According to the syndrome differentiation， the deficiency in origin and excess in superficiality， the similarities and differences of pathogen are distinguished， and then the prescription is selected to treat the bi syndrome layer by layer，so as to remove pathogen without damage healthy qi.