Abstract: This paper carries out a bibliometric analysis of the literatures of usnic acid published in the past 30 years to discuss its current research status, hotspots and development trend. The relevant research literatures of usnic acid published on Web of Science from 1990 to 2021 are retrieved. Then, scientometrics tools like VOSviewer1.6.17 and CiteSpace5.8.R3 are used to create network knowledge maps of usnic acid, and co-occurrence and cluster analysis of countries, authors and keywords are done. Finally, a total of 998 foreign articles are included in the quantitative analysis. The annual publication volume of usnic acid-related research fields is increasing year by year, showing a trend of dynamic development, with a high research interest especially in the past 15 years. Research authors from 76 countries around the world have formed a number of close contact teams. China ranks the fifth in the number of foreign literatures published from 1990 to 2021, and has cooperated with 15 countries in usnic acid researches. In the past 30 years, scholars from all over the world have carried out comprehensive researches on usnic acid in terms of natural sources, extraction and separation, pharmacological activity and toxicity. In the past 5 years, compared with the early and mid-term research stages, the research hotspots of usnic acid have gradually shifted from sources, extraction and isolation, anti-inflammation and anti-bacteria, and antioxidant activities to anti-tumor activity evaluation and mechanism researches, and the research of new delivery systems transforms. A visualization method is used to analyze usnic acid related literatures, and the research status of usnic acid is displayed in the form of knowledge graphs, which can better predict the research frontier, hotspots and development trend of usnic acid, and provide reference and suggestions for the follow-up research.