Periodontitis is a common oral disease and the leading cause of tooth loss in adults. The gingival epithelium is the first line of defense against external invasions. The occurrence and development of periodontitis are closely related to the invasion and destruction of the gingival epithelium by various pathogenic bacteria. Research has demonstrated that periodontitis-associated pathogens destroy the gingival epithelium,invade deep tissues,and trigger inflammatory responses through a series of virulence factors. Among them, Porphyromonas gingivalis is the main cause of periodontitis. This article reviews the regulatory effects of Porphyromonas gingivalis on the gingival epithelium, with the aim of providing a reference for the treatment of periodontitis.