Ulcerative colitis is a chronic inflammatory bowel disease，and its pathogenesis has not been fully clarified，which is mainly caused by genetic susceptibility，environmental factors，abnormal immune response，microorganisms and other risk factors. Ulcerative colitis is mainly treated by anti - inflammatory and immunosuppression，but there are some problems such as inevitable side effects，high recurrence rate，strong drug resistance and high price. The active ingredients of natural drugs have the characteristics of multi - target，high curative effect and little side effect，and have become an important research object in the treatment of ulcerative colitis. This article reviews the pharmacological action and mechanism of natural active ingredients in the treatment of ulcerative colitis in recent years，hoping to put forward more targeted ideas or strategies for the treatment of ulcerative colitis and provide theoretical basis for the research and development of new drugs.