Objective: This systematic review and meta-analysis was undertaken to evaluate the efficacy of antibacterial photodynamic therapy (aPDT) in the treatment of periodontitis in type-2 diabetes mellitus (T2DM) patients and to provide better treatment for patients with T2DM complicated with periodontitis. Methods: The PubMed, Cochrane, Embase, Web of Science, CNKI, CBM, and Wanfang databases were searched for relevant randomized controlled trials (RCTs). RevMan 5.3 was applied for the meta-analysis, and a systematic evaluation was conducted. Results: A total of 8 RCTs were included. The results showed that compared to simple subgingival scaling and root planing (SRP), aPDT assisted SRP had a better effect on improving the probing depth (PD) at 3 months after treatment, The difference was statistically significant [WMD=-0.32,95%CI（-0.45, -0.2）, P < 0.05], but 6 months after treatment, there was no significant difference in the two groups [ WMD=-0.15,95%CI（-0.40, 0.10）,P=0.23]. During the 6-month follow-up period, there were no significant differences in the clinical attachment level (CAL), bleeding on probing (BOP) or hemoglobin A1c (HbA1c) between the two groups (P> 0.05). Conclusion aPDT-assisted periodontal nonsurgical treatment in T2DM patients can improve PD in the short term but has no significant effect on the improvement of CAL, BOP and HbA1c.