Objective To investigate the changes of blood lipid and glycosylated hemoglobin (HbA1c) levels in obese type 2 diabetes (T2DM) patients and their relationship with insulin resistance (Homa-IR). Methods A total of 120 cases of T2DM newly diagnosed in Motuo County, Tibet from February to October 2022 were selected as the observation group. According to BMI, the patients were divided into diabetes normal weight group (46 cases), overweight group (43 cases) and obesity group (31 cases); 145 healthy subjects were selected as the control group. The levels of HbA1c, fasting blood glucose (FPG), fasting insulin (FINS), serum total cholesterol (TC), triglycerides (TG), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C) were detected in the study subjects, and Homa-IR and Homa-β indices were calculated. The height, weight, and abdominal circumference were measured. The differences in the levels of the above indicators between the observation group patients and the control group, as well as among various subgroups within the observation group were compared. The influencing factors of Homa-IR in obese T2DM patients were analyzed. Results Compared with the control group, a significant increase in BMI, abdominal circumference, blood pressure, HbA1c, FBG, FINS, TC, TG, LDL-C, UA, visceral fat area, and the levels of Home-IR and Home-β was found in the observation group (all P<0.05). There were significant differences in BMI, abdominal circumference, and the levels of FINS, Homa IR, Homa-β, and HbA1c in diabetes patients with different BMI (all P<0.05). Correlation analysis showed that TG levels in obese T2DM patients in the observation group were significantly correlated with HbA1c (r=0.396, P=0.027), Homa-IR (r=0.405, P=0.024), and Home-β (r=-0.401, P=0.025); LDL-C was significantly correlated with Homa-IR (r=0.411, P=0.022) and Homa-β (r=-0.412, P=0.021); HbA1c was significantly positively correlated with BMI (r=0.371, P=0.040). Conclusion Insulin resistance is closely related to TG, LDL-C, and BMI in obese T2DM patients from the Motuo ethnic minority of Tibet, suggesting that these factors may play a role in the occurrence of T2DM.