Objective To investigate the correlation between coagulation function and peripheral arterial plaques in patients with type 2 diabetes mellitus. Methods A total of 269 patients with type 2 diabetes mellitus who were hospitalized in Department of Endocrinology of our hospital from May to Aug. 2022 were enrolled and divided into carotid plaque group (131 cases) and non-carotid plaque group (138 cases), or lower extremity arterial plaque group (134 cases) and non-lower extremity arterial plaque group (135 cases). General data and coagulation function indexes of the patients between groups were compared. Independent influencing factors of type 2 diabetes mellitus complicated with peripheral arterial plaques were evaluated using logistic regression analysis. Results Compared with the non-carotid plaque group, the fibrinogen level was significantly higher in the carotid plaque group (3.15 [2.79, 3.79] g/L vs 2.99 [2.66, 3.42] g/L, P＝0.005). Logistic regression analysis showed that fibrinogen was an independent risk factor of carotid plaque in type 2 diabetes mellitus patients (odds ratio＝ 1.338，95% confidence interval 1.061-2.078, P＜0.05). There was no significant difference in coagulation function indexes between the lower extremity arterial plaque and non-lower extremity arterial plaque groups (all P＞0.05). Conclusion There are different correlations between peripheral arterial plaques in different parts and coagulation function in type 2 diabetes mellitus patients; those with carotid plaque have higher fibrinogen level, and fibrinogen is an independent risk factor for carotid plaque after controlling other confounding factors; however, there is no correlation between lower extremity arterial plaque and coagulation function indexes.