Aim To explore the correlation between monocyte to high density lipoprotein ratio (MHR) and type 2 diabetes mellitus (T2DM) with arteriosclerosis obliterans (ASO) of lower extremity. Methods 340 T2DM patients admitted to our hospital from February 2017 to January 2019 were selected as research objects. According to the quartile of MHR, the patients were divided into four groups:group A (n＝85):MHR＜0.61×10⁹; group B (n＝85):MHR (0.61-0.90)×10⁹; group C (n＝85):MHR (0.91-1.17)×10⁹; group D (n＝85):MHR＞1.17×10⁹. The baseline data of patients were analyzed by single factor analysis, and Logistic regression analysis was carried out for the single factor with statistical significance, in order to analyze the correlation between MHR and ASO. The independent risk factors of ASO were discussed and the prediction model was established. ROC curve was used to evaluate the diagnostic efficiency of MHR to ASO. Results The incidence of ASO in group A, group B, group C and group D were 21.18%, 24.70%, 47.06% and 56.47% respectively. There was significant difference in the incidence of ASO among the four groups (P＜0.001). The differences of body mass index, MHR, course of disease, monocyte, fasting blood glucose, glycosylated hemoglobin A1 (HbA1c), serum creatinine, blood urea nitrogen, ankle brachial index (ABI), homocysteine (Hcy), serum uric acid (SUA), fasting insulin, apolipoprotein A1, apolipoprotein B, homeostasis model assessment index of insulin resistance (HOMA-IR), triglyceride, high density lipoprotein cholesterol and low density lipoprotein cholesterol (LDLC) were statistically significant among the four groups (P＜0.05). Logistic regression analysis showed that MHR, Hcy, HOMA-IR, LDLC, HbA1c and SUA were independent risk factors for ASO (P＜0.05). Pearson correlation analysis showed that there was a negative correlation between MHR and ABI (r＝－0.742, P＜0.001). ROC curve showed that the cut-off value of MHR for ASO diagnosis was 0.91×10⁹, the sensitivity was 79.53%, the specificity was 81.22%, and the area under curve was 0.815. Conclusion MHR is an independent risk factor for the occurrence of ASO in T2DM patients, which has a positive correlation with ASO, and has a certain value for the prediction and evaluation of ASO.