Objective: To evaluate the diagnostic value of color Doppler ultrasound in the diagnosis of diabetic lower extremity vascular diseases. Methods: 48 patients with diabetic lower extremity vascular disease admitted in our hos-pital from September 2018 to September 2019 were included in the study and divided into the observation group, and another 48 patients with the same period of health examination in our hospital were included in the study and divided into the control group. Both groups used color Doppler ultrasound to detect the blood flow of lower extremity vessels. The incidence of blood flow, vascular diameter and stenosis, occlusion and arteriosclerosis of the lower extremity were observed. Results: The blood flow and vascular di-ameter of the lower extremity in the observation group were significantly lower than those in the control group (p < 0.05). The incidence of vascular stenosis, vascular occlusion, thrombus, intimal thickening and plaque in the observation group was 85.42%, 22.92%, 10.42% and 93.75% respectively, which was significantly higher than that in the control group was 10.42%, 0.00%, 0.00% and 14.58% (p < 0.05). The incidence of lower extremity vascular lesions in the observation group was significantly higher than that in the control group (p < 0.05). Conclusion: Color Doppler ultrasound is of high diagnostic value in the diagnosis of diabetic lower extremity vascular diseases, and can be used to determine the blood flow of the lower extremity and the inner diameter of popliteal artery, thigh artery, dorsalis pedis artery and so on. At the same time, it can also clearly show the specific situation of vascular occlusion, arteriosclerosis and thrombosis, which is of great signif-icance for the prevention and diagnosis of lower extremity vascular lesions, and can provide the basis for the treatment of lower extremity vascular lesions.