Alfalfa is an important crop for feed and green manure. To grasp the development process and current hot spots, the papers in the Web of Science were used as the data source. Based on CiteSpace, the papers on alfalfa research from 2012 to 2021 were visually analyzed from the aspects of literature volume, national contribution, institutional contribution, author group analysis, theme category and keywords, which provided a theoretical reference for alfalfa researchers to track the research frontier of alfalfa and grasp the research direction. The results showed that alfalfa research was paid more and more attention in recent years. The United States was the main country in alfalfa research. The cooperation between the United States and China, Spain and France, and France and Brazil in the field of alfalfa research was close. Most research institutions and researchers were closely linked, forming a core group of authors internationally, but most authors were scattered. The research hotspots of alfalfa mainly focused on the factors affecting the growth and quality of alfalfa, the influence of alfalfa on soil, the application of alfalfa in silage, the application of alfalfa in green manure, and the quality detection and evaluation of alfalfa.