Objective Based on mitochondrial autophagy mediated by FOXO1/PINK1 signaling pathway, the possible mechanism of islet cell senescence in obese diabetes mellitus was explored. Methods Thirty SD rats were randomly divided into control group, obesity diabetes group and FOXO1 activation group, with 10 rats in each group. During this period, the general state of rats in each group was observed and recorded. Glucose level of rats in each group was detected by Sugar test kit, and insulin level of rats in each group was detected by ELISA kit and transmission electron microscope. The mRNA and protein levels of autophagy pathway related proteins FOXO1, PINK1, Parkin, LC3Ⅱ and aging related proteins p16, p21 and Rb in the pancreatic tissues of rats in each group were detected by RT-qPCR and Western blotting. Results Compared with the control group, the mRNA and protein levels of FOXO1, PINK1, Parkin, LC3Ⅱ in pancreatic tissue of rats with obesity diabetes group decreased(P＜0.05) Compared with the control group, the daily food intake, water intake and urine volume of rats in the obese diabetes group were increased (P＜0.05). Compared with obese diabetic rats, the daily food intake, water intake and urine volume of rats in FOXO1-activated group were decreased (P＜0.05) Compared with the control group, fasting blood glucose and fasting insulin contents were increased and insulin sensitivity index was decreased (P＜0.05). Compared with the obese diabetic group, the contents of fasting glucose and fasting insulin in FOXO1-activated group were decreased, and the insulin sensitivity index was increased (P＜0.05) The results of transmission electron microscopy showed that compared with the control group, the number of insulin particles in the islet beta cells of the obese diabetic group was significantly increased. Compared with the obese diabetic rats, the number of insulin particles in the islet beta cells of the FOXO1-activated rats was significantly decreased. Compared with the control group, the mRNA levels of FOXO1, PINK1, Parkin and LC3Ⅱ in pancreatic tissue of rats with obesity diabetes group were decreased (P＜0.05); Compared with obese diabetic rats, mRNA levels of FOXO1, PINK1, Parkin and LC3Ⅱ in FOXO1-activated rats increased (P＜0.05). Compared with the control group, the mRNA and protein levels of age-related genes p16, p21 and Rb were increased in the pancreatic tissue of rats with obesity diabetes group (P＜0.05). Compared with obese diabetic rats, the mRNA and protein levels of p16, p21 and Rb in FOXO1-activated rats decreased (P＜0.05)Conclusion Activation of FOXO1 can activate mitochondrial autophagy in pancreatic tissue of obese diabetic rats, down-regulate the genes related to aging of islet cells, and improve the general state muscle glucose index of rats, which may be related to the mitochondrial autophagy mediated by FOXO1/PINK1 signaling pathway