Objective To analyze the literature of leech in medicine using CiteSpace knowledge map,comprehensively understand the research status,hotspots and development trends of component analysis and pharmacological effects of leech,and provide reference for researchers in the field of leech.Methods CiteSpace 6.1 R3 software was used to analyze the relevant literature of leech in the field of medical research in CNKI and Web of Science databases from 1996 to 2022.The bibliometric and visual analysis of the number of articles,authors,research institutions,keyword co-occurrence,clustering and emergence were carried out.Results A total of 1 115 Chinese articles in CNKI database and 237 English articles in Web of Science database were included.The analysis of Chinese and English literature showed that the author Shi Hongzhuan had the largest number of Chinese articles,and the German author Hildebrandt had the largest number of English articles.Shandong University of Traditional Chinese Medicine and Chinese Academy of Sciences were the institutions with the largest number of articles in Chinese and English respectively.The country with the most published English literature is the United States.Chinese and English keyword co-occurrence and cluster analysis showed that Chinese literature focused on the study of its active ingredient hirudin,including molecular structure,pharmacological efficacy,mechanism of treating thrombosis,coronary heart disease,kidney disease and other diseases,and paid attention to the differences in the active ingredients of different types of leeches.In addition,English literature focused on the clinical external use of living leeches.The emergence of keywords suggested that the mechanism of action,the search and synthesis of hirudin analogues,and the pharmacodynamic mechanism of compatibility application were not only the current research hotspots,but also the future hot spots.Conclusion The analysis of leech components,the pharmacological mechanism of leech in the treatment of cardiovascular diseases,chronic kidney diseases and other diseases have always been the research hotspots.Hirudin analogues,the pharmacodynamic mechanism of compatibility application,network pharmacology,molecular docking and so on may be the future research hotspots and trends of leeches.