Background: Mesenchymal stem cell (MSC) therapy shows great promise for diabetic kidney disease (DKD) patients. Research has been carried out on this topic in recent years. The main goal of this paper is to evaluate the therapeutic effects of MSCs on DKD through a meta-analysis and address the mechanism through a systematic review of the literature.Method: An electronic search of the Embase, Cochrane Library, ISI Web of Science, PubMed and U.S National Library of Medicine (NLM) databases was performed for all articles about MSC therapy for DKD, without species limitations, up to January 2020. Data were pooled for analysis with Stata SE 12.Result: The MSC-treated group showed a large and statistically significant hypoglycemic effect at 1 week, 2 weeks, 3 weeks, 1 month, 2 months, 3 months and 6 months. Total hypoglycemic effect was observed (SMD=-1.954, 95%CI: -2.389 to -1.519, p<0.001). The overall effects on serum creatinine (SCr) and blood urea nitrogen (BUN) were analyzed, suggesting that MSC decreased SCr and BUN and mitigated the impairment of renal function (SCr: SMD= -4.838, 95%CI: -6.789 to -2.887, p<0.001; BUN: SMD= -4.912, 95%CI: -6.402 to -3.422, p<0.001). Furthermore, MSC therapy decreased the excretion of urinary albumin. Fibrosis indicators were assessed, and the results showed that transforming growth factor-β, collagen-I, fibronectin and α-smooth muscle actin were significantly decreased in the MSC-treated group compared to the control group.Conclusion: MSCs may improve glycemic control and reduce SCr, BUN, and urinary protein. MSCs can also alleviate renal fibrosis. MSC therapy is a potential treatment for DKD.