Aim To investigate the correlation between carotid atherosclerotic plaque and bone mineral density (BMD) in patients with type 2 diabetes mellitus (T2DM). Methods Analysing the clinical data of 720 patients with T2DM, the selected subjects were divided into male group and female group, and each group was further divided into normal bone mass group and osteopenia group, carotid artery plaque group and without carotid artery plaque group. Results In the male osteopenia group (77 cases), there were 68 cases of atheromatous plaque (88.31%). Compared with the normal bone mass group (164 cases), the incidence of atherosclerotic plaque in the osteopenia group was significantly increased (P<0.05), and the bone mineral density (BMD) in the plaque formation group was significantly decreased (P<0.05). In the female osteopenia group (255 cases), 191 (74.90%) had atherosclerotic plaques. Compared with normal bone mass group (224 cases), the incidence of atherosclerotic plaques in osteopenia group was significantly increased (P<0.05), and BMD in plaque formation group was significantly decreased (P<0.05). Logistic regression analysis showed that the influence factors of male bone mass reduction included age (OR=1.059, P=0.002), BMI (OR=0.853, P=0.004), FBG (OR=1.138, P=0.044), presence of carotid artery plaque (OR=2.514, P=0.035); the influencing factors of female bone mass reduction included age (OR=1.117, P=0.000), menopause age (OR=0.946, P=0.031), BMI (OR=0.910, P=0.003). Conclusions Carotid atherosclerotic plaque is closely related to bone loss in T2DM patients, which often occurs together in women as a result of the existence of common risk factors. However, in male patients, the formation of carotid atherosclerotic plaques is a risk factor for osteoporosis. Therefore, the development of carotid atherosclerosis is often accompanied by changes in bone mass, which is prone to osteoporosis.