Escherichia coli Nissle1917 (EcN), as a probiotic, is mainly used to treat a variety of gastrointestinal disorder including inflammatory bowel disease, chronic constipation. EcN prevents human intestinal epithelial cells from adherent and invasion of evasive pathogen, and protects intestinal mucosal barrier and inhabits pathological inflammation. EcN also enhances intestinal immune function and regulates cytokine secretion. Recently, EcN has shown anti-cancer efficacy via tumor targeting ability. Furthermore, EcN enhances the tumor targeting effect when combined with chemotherapeutic drugs, providing a promising application of EcN in precise treatment of cancer. EcN provides a great potential in developing novel approach of cancer treatment.