As the standard of living of our people improves and the life expectancy increases, atherosclerosis diabetes is becoming more and more common. Both are systemic diseases, which are the main culprits of myocardial infarction, cerebral infarction and ischemic necrosis of the lower extremities. Complications of diabetes cause severe lower extremity ischemia, producing lower extremity pain and even necrosis, ultimately leading to tragic amputations. The traditional treatment for lower extremity ischemia is surgical arterial bypass, but there has been no effective solution for patients who cannot be surgically bypassed. Previous studies have found that transplantation of bone marrow mononuclear cells into an ischemic limb results in the formation of local vascular endothelial cells that produce new blood vessels. These new vessels are connected to the collateral circulation vessels in the proximal limb, restoring the blood supply to the distal limb, a treatment we call “cell bypass. “Cell bypass” is simple and safe, and can be done under local anesthesia. The treatment effect is remarkable, and autologous cell transplantation does not produce any adverse reactions; the pain relief effect will be obvious one week after the treatment, and the new blood vessels will be formed after one month, and the blood supply to the limb will be improved, thus avoiding the development of ischemic necrosis of the lower limb caused by atherosclerosis and diabetes. even amputation. The application of autologous bone marrow stem cell transplantation (cell bypass) in the peripheral vascular surgery department of Beijing Dongzhimen Hospital for the treatment of atherosclerosis and diabetic severe lower limb ischemia has achieved satisfactory clinical results and brought good news to patients.