Abstract： Objective： To study the medication rules of Professor ZHANG Xiaoling in treating thyroid cancer based on data mining techniques. Methods：The data on thyroid cancer patients treated by Professor ZHANG Xiaoling in the outpatient department of Ningbo Municipal Hospital of Traditional Chinese Medicine from October 2018 to September 2023 were collected， and 1 703 effective prescriptions were obtained. Excel software and Ancient and Modern Medical Records Cloud Platform (V2.2.1) were used to count the frequency， natures and flavors， meridian entries and efficacy of Chinese medicinals. The cluster analysis was conducted on highly used Chinese medicinals. Core medicinal combinations were extracted. Results： A total of 177 Chinese medicinals were involved，and the total frequency of medication was 29 391 times. There were 21 high-frequency Chinese medicinals with frequency of medication ≥ 400 times， such as Bupleuri Radix，Lilii Bulbus，Astragali Radix. The top three medicinal properties are slightly cold，warm and neutral， the top three medicinal flavors are sweet， bitter and pungent， and the top five meridian entries are the liver， lung， stomach， spleen and kidney. Their efficacy is mainly clearing heat and detoxifying， activating blood and relieving pain， strengthening muscles and bones， engendering fluid and nourishing blood， and soothing the liver and releasing constraint. Four cluster combinations of Chinese medicinals were obtained by the cluster analysis. The core medicinal combinations were Bupleuri Radix， Astragali Radix， Lilii Bulbus， Atractylodis Macrocephalae Rhizoma， Lycii Fructus， Ophiopogonis Radix， Salvia Miltiorrhizae Radix et Rhizoma，Rabdosiae Rubescentis Herba，Ranunculi Ternati Radix，Epimedii Folium， Cuscutae Semen and Glycyrrhizae Radix et Rhizoma. Conclusion：Professor ZHANG Xiaoling treats thyroid cancer by soothing the liver as the core，taking into account the five internal organs. The treatment method emphasizes clearing heat and resolving toxins，activating blood and resolving phlegm，the medicinals used are neutral，using both warming and clearing method and paying attention to the balance of yin and yang.