Objective To investigate the effect of Er,Cr:YSGG water laser combined with concentrated growth factor (CGF) on inflammatory factor levels in gingival crevicular fluid of patients with periimplantitis. Methods A total of 72 patients with peri-implantitis admitted to the Department of Stomatology, Ganzhou People’s Hospital from September 2024 to July 2025 were selected, and they were divided into the control group and the observation group by the random number table method, with 36 patients in each group. The control group received conventional treatment, and the observation group was additionally treated with Er,Cr:YSGG water laser and CGF on the basis of the control group. The treatment effect, periodontal-related indicators, inflammatory factor levels in gingival crevicular fluid, repair satisfaction, implant stability and complications were compared between the two groups. Results The total effective rate of the observation group was 94.44%, which was higher than 77.78% of the control group (P <0.05). At 6 months after treatment, the PD, mSBI, mPLI, MBL and the levels of IL-1β, TNF-α, IL-6 in gingival crevicular fluid of the observation group were lower than those of the control group, and the ISQ and each repair satisfaction score were higher than those of the control group (P <0.05). The incidence of complications in the observation group was lower than that in the control group (P <0.05). Conclusion Er,Cr:YSGG water laser combined with CGF achieves definite efficacy in the treatment of peri-implantitis. It can improve periodontal indicators and inflammatory status, enhance implant stability and patient satisfaction, with favorable safety.