Objective To systematically review the efficacy of photodynamic therapy combined with initial periodontal therapy in the treatment of periodontitis. Methods PubMed, Embase, Cochrane Library, and Web of Science were searched from database inception to June 30, 2022. The randomized controlled studies of photodynamic therapy combined with the treatment of peri implantitis were collected and evaluated by two participants. After the researchers independently screened the literature according to the inclusion and exclusion criteria, extracted the data and evaluated the quality, the RevMan5.3 software was used to conduct a Meta analysis of the studies that met the inclusion criteria. Results A total of 636 articles were screened, resulting in 8 included studies. Meta analysis indicated that PDT combined with basic periodontal therapy improved clinical efficacy. After 3 months, the intervention group exhibited superior outcomes in bleeding, probing depth, and clinical attachment level compared to controls (P<0.05). After 6 months, bleeding, probing depth, and bone loss favored the intervention group (P<0.05). At 12 months, bone loss was significantly reduced in the intervention group (P<0.05). Conclusions PDT combined with periodontal basic treatment for implant periodontitis significantly improves bleeding on probing, probing depth, bone loss, and clinical attachment level.