Inflammatory bowel disease (IBD) is a global idiopathic disease involving the ileum, rectum, and colon. The early clinical symptoms of IBD include abdominal discomfort, diarrhea, hematochezia, fever, fatigue, and weight loss. The diagnosis of IBD is based on a comprehensive evaluation of relevant clinical manifestations, endoscopic examination result, and histopathological characteristics of tissue specimens. Biological agents, oral corticosteroids, salicylic acid, and surgery are the main conventional treatments for IBD. Considerable progress has recently been made in elucidating the pathogenesis of IBD. In clinical practice, complex interactions among genetic susceptibility, environmental factors, and the intestinal mucosal barrier are thought to lead to abnormal oxidative stress, autophagy, and a mucosal immune response. This paper briefly summarizes and expounds research progress into genetic and environmental factors, intestinal mucosal barrier function, oxidative stress, autophagy dysfunction, and the adaptive immune response, to provide a basis for further research and the development of treatment method and improvements in clinical efficacy.