Crohn’s disease and ulcerative colitis are two forms of inflammatory bowel diseases. They are autoimmune disorders caused by excessive inflammatory response to antigens in the intestine. In addition to the hygiene hypothesis which suggests the potential application of helminthic infection in the treatment of inflammatory bowel diseases, helminthic infection has shown preventive and treatment effects in animal models of inflammatory bowel disease. Clinical trials have been initiated. For example, Trichuris suis ova infection at a certain dose has a promising efficacy in the treatment of inflammatory bowel diseases. Helminthic infection may also have adverse effects. Therefore, helminth-derived immunomodulatory molecules are needed to overcome these problems. It is traditionally considered that the Th1/Th2 axis is involved in the mechnisms of the efficacy of helminthic infection. More recent research has pointed out the much more participation of the Tregs/Th17 axis. The mechanisms may also involve other palyers such as mucosal barrier, Toll like receptor and macrophages. This paper reviews the effect and mechanism of helminthic infection on the prevention and treatment of inflammatory bowel disease.