To investigate the commonly used traditional Chinese medicine(TCM) methods and medication rules of TCM in the treatment of oral ulcer induced by malignant tumor chemotherapy in the past two decades.Methods:Through the combination of manual and computer retrieval，research articles with the themes of “chemotherapeutic oral ulcer”，“chemotherapeutic oral mucositis”，and “traditional Chinese medicine” were retrieved from CNKI，CSPD，and CCD from 2001 to 2021.The required database was established by reading abstracts and NoteExpress automatic screening and checking.Frequency statistics，correlation analysis，and hidden Dirichlet allocation(LDA) statistical methods were adopted to analyze the method of administration，drug frequency，properties，flavors，and meridian tropism of drugs，commonly used drug pairs，and core drug combinations in the clinical TCM treatment of chemotherapy-induced oral ulcer.Results:Ninety-three research articles were included，involving 96 prescriptions and 141 drugs.The main methods of administration were oral decoctions and mouthwash with liquid medicines.The guiding principle of medication was the selection of heat-clearing and deficiency-tonifying drugs，represented by Glycyrrhizae Radix et Rhizoma，Coptidis Rhizoma，and Rehmanniae Radix.The drugs were mainly sweet，bitter，and cold，acting on the lung，stomach，heart，and spleen meridians.Conclusion:This study comprehensively analyzed drug administration methods and medication rules in the treatment of chemotherapy-induced oral ulcer in the clinical literature of TCM and found that qi deficiency，yin deficiency，and hyperactivity of fire are the main pathogenesis of this disease.Therefore，the treatment should be based on invigorating qi，clearing heat，nourishing yin，and increasing fluid.