(1) Restrict activities, reduce weight, elevate the affected limb to facilitate blood return to the lower limb and reduce edema. (2) Strictly control blood glucose, insulin to apply the limb is better, and actively correct ketoacidosis, hypoproteinemia, cardiac, cerebral and renal complications and various adverse factors that affect gangrene healing. (3) Local debridement: removal of necrotic tissue, placement of drainage, routine disinfection and drug changes, etc. (4) For severe vascular lesions, on the basis of conservative treatment, vascular revascularization should be performed. The methods include: vascular bypass, endarterectomy, tipped large omentum graft, percutaneous transluminal angioplasty, etc. (5) For gangrenous patients with pain at rest and extensive vascular lesions that cannot be revascularized, decisive amputation should be performed, and it is best to perform angiography before amputation to determine the plane of amputation. (6) Hyperbaric oxygen therapy (HBD) can improve the vascularization of new tissues, increase the synthesis of collagen, improve the bactericidal effect of neutrophils, and also promote the synthesis of platelet-derived factor, which has the effect of promoting wound healing. If combined with lung infection, hyperbaric oxygen therapy is not suitable. (7) Photon therapy instrument local irradiation: Using the enzymatic reaction of cells brought about by the high-energy photon effect to improve the aerobic respiration of tissue cells, thus rapidly and significantly improving the recovery of the traumatized tissue and the healing of the wound. It is especially useful for the healing of chronic wounds that are complex and difficult to heal. At present, it is mainly used for the treatment of diabetic foot ulcers and various decubitus ulcers. (8) Application of negative pressure suction device for trauma: Form a closed gap on the trauma surface and use the method of continuous negative pressure suction to drain out abscess or other inflammatory media from the trauma surface to reduce local redness, swelling and pain and promote the growth of granulation tissue. Compared with traditional drug exchange and drainage, it has the advantages of quick effect, good efficacy and less patient pain, which can significantly shorten the hospitalization time and treatment cost of diabetic foot disease patients. (9) Strengthen patient education, reasonable foot care as well as prevention of injury from external sources.