OBJECTIVE: Diabetes mellitus (DM) is a grave autoimmune disorder because of no insulin self-generation. Currently, mainly clinical methods exist, serious adverse effects leading to stem cell therapy are considered. The mesenchymal stem cells (MSCs), require high differentiation capacity and are judged as crucial in DM treatment. The meta-analysis aimed to systemically analyze the particular types of MSCs which play a more important role in DM and which DM is treated more effectively. METHOD: A systematic review was conducted on the published literature, clinical trials and observational studies, utilizing databases such as PubMed, Embase, Cochrane and clinicaltrial.gov. RevMan software was adopted to draw Forest Plot and Funnel Plot, and subgroup analysis were employed to evaluate heterogeneity between different groups. RESULTS: We identified the meta-analyses of 34 unique random controlled trials and divided our own systematic reviews into 8 groups. The MSCs were associated with placebo (OR = 2.79, 95% CI [1.63, 4.75]), Standard Clinical Treatment (SCT) (OR = 4.12, 95% CI [2.76, 6.14]), and monocyte (OR = 6.52, 95% CI [3.56, 9.48]). The comparison between Autologous MSCs and Allogenic MSCs (OR = 4.64, 95% CI [3.42, 6.31]), Autologous BMMSCs and other MSCs (OR = 5.28, 95% CI [3.64, 7.66]), Allogenic ASCs and UCMSCs (OR = 3.54, 95% CI [1.83, 6.86]), Type I DM and Type II DM (OR = 3.10, 95% CI [1.79, 5.38]), intravenous injection and other injections (OR = 4.81, 95% CI [3.34, 6.94]), diabetic foot ulcers and diabetic neurological disease (OR = 3.88,,95% CI [2.53,5.95]). CONCLUSION: Current evidence suggests that MSCs hold significant potential for treating DM, demonstrating considerably high safety and efficacy. MSCs exhibit higher therapeutic benefits compared to monocytes, with autologous MSCs offering better clinical outcomes than allogenic sources. MSCs (BMMSCs) proved more effective than other types of MSCs. However, no significant differences were observed between adipose-derived MSCs (ASCs) and umbilical cord-derived MSCs (UCMSCs) in the allogeneic setting. Moreover, MSCs show more pronounced therapeutic effects in Type II DM, and the difference among the injection methods is minimally observed. In conclusion, the research scope on DM is relatively limited in this study and further research is necessary to improve the reliability of the estimates.