With the increasingly wide clinical application of oral implantation, peri-implantitis, as a major complication leading to implant loosening and even implant failure, seriously impairs the long-term therapeutic effect of implantation. At present, the pathogenesis of this disease remains to be systematically summarized, and horizontal comparative analysis of various diagnosis and treatment modalities is insufficient. This paper discusses the pathogenesis of peri-implantitis from the perspectives of microecological imbalance, biofilm and immune disturbance, summarizes the advantages and disadvantages of conventional and novel diagnostic techniques, and reviews the research advances in basic therapy, surgical therapy and targeted therapy. It aims to clarify its core pathogenesis, compare the clinical value of different diagnosis and treatment regimens, and provide theoretical evidence for early prevention, precise and individualized treatment of peri-implantitis.