The aim of this study is to objectively assess the research field of humic acid applications in global agriculture. By precisely summarizing the focal points and inadequacies of current research, it endeavors to offer references for researchers and decision-makers. The relevant literatures from the Web of Science (WOS) regarding humic acid in agricultural applications over the past 30 years were employed, through bibliometric methods, systematic quantitative and qualitative analyses are conducted from multiple aspects, including publication volume, countries/regions, authors, disciplines, publishing institutions, co-cited literature, and keyword analysis. The results indicate that the research on humic acid in agricultural applications initiated relatively early and has sustained a high level of research enthusiasm. Although China ranks first globally in the number of published papers, there remains substantial space for enhancing its scientific research influence. Presently, research hotspots are concentrated on the environmental geochemical behavior of humic acid, its application in soil remediation, the classification and property characterization of humic acid, as well as its application in crop cultivation. Overall, the research on humic acid agricultural applications is gradually evolving from merely evaluating humic acid properties to comprehensively assessing the environmental and economic benefits of its application effects. Looking forward, optimizing the artificial synthesis and preparation process of humic acids will be the crucial research directions and objectives. In-depth exploration in this area is anticipated to boost the efficient and accurate application of humic acid in agriculture, thereby providing a solid technical underpinning for the sustainable development of the agricultural sector.