Primary pterygium is a non-neoplastic degenerative tissue that grows subepithelially, and its pathogenesis is mainly related to ultraviolet exposure, however, the full mechanism of primary pterygium remains unclear. In recent years, with the development of medical research, it is found that the occurrence and development of primary pterygium are closely related to a variety of factors. Viral infection, oxidative stress, inflammatory response, inactivation of tumor suppressor genes, DNA methylation and other factors have been shown to be involved in the pathogenesis of pterygium. In addition, imbalances of apoptosis and proliferative proteins, extracellular matrix regulators, and epithelial-mesenchymal cell transformation also play important roles in the pathogenesis of primary pterygium. These can lead to abnormal cell growth and division, which in turn induces the formation of pterygium. However, the interaction between these factors and their specific mechanisms of action in the pathogenesis process still need to be further studied. In this article it reviews the current pathogenesis of primary pterygium, and deeply explores the pathogenesis of primary pterygium and the interaction of different related factors in the pathogenesis of primary pterygium. By understanding the role of different factors in the pathogenesis process, we can provide more precise and effective prevention and treatment strategies for clinical practice, and better treatment outcomes and quality of life for patients.