Adherent-invasive Escherichia coli (AIEC) has recently attracted more attention because it is closely related to the pathogenicity of human inflammatory bowel disease (IBD). AIEC possesses a multitude of virulence factors. Considering these virulence factors belonging to various virulence groups, including adhesins, invasins, toxins, protectins, and siderophore-mediated iron acquisition, this review summarizes the current knowledge of how the major virulence factors assisting in AIEC survive in, adhere to, and invade host cells. A comprehensive understanding of the interaction of virulence factors with host cells will provide us a new therapeutic strategy for IBD prevention and treatment.