Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease that diabetes mellitus is one of its major risk factors. MiR-126 as an endothelial cells specific miRNA plays a main role in angiogenesis. The objective of this study was to find a promising treatment by increasing therapeutic potential of adipose tissue mesenchymal stem cells (AT-MSCs) with microRNA-126 in diabetic mouse model with critical limb ischemia. AT-MSCs were isolated from male C57BL/6 mouse and characterized. The cells were infected with miR-126 recombinant lentiviral vectors. Diabetes mellitus type 1 was induced and CLI was created in the animals. Animals were divided in different groups to receive PBS, MSCs, miR-126, and MSCmiR-126 and after the experiment, behavioural tests, cell survival, real-time PCR, and histopathological analysis were assessed. The results of function scores, VEGF-A level, and histopathology data demonstrated that the miR-126 treated group was better than PBS and MSCs groups. The expression of PIK3R2 and SPRED1 were decreased in miR-126 group compared to the control group. Our results showed that MSCsmiR-126 can live longer than MSCs in the gastrocnemius muscle. We conclude that mice treated with MSCsmiR-126 in functional tests showed better results and also the expression of VEGF-A and Microvessel density in them were higher than other groups. This study suggested that AT-MSCs overexpressing miR-126 could be an efficient therapeutic approach for angiogenesis in CLI with diabetes by downregulating SPRED1 and PIK3R2 and increasing secretion of angiogenic cytokines which can prolong the MSC survival.