Diabetic foot is one of the severe chronic complications of diabetes, generally referred to as the abnormalities in the lower limbs caused by diabetic vascular neuropathy. Diabetic foot with gangrene of the extremity due to concurrent infection is referred to as diabetic foot with gangrene of the extremity, representing a serious stage in the progression of diabetic foot. The main symptoms of diabetic foot include: first, subcutaneous fat atrophy, thinning of the skin, common pigmentation spots on the shin, no hair on the feet and toes, and thickening of the toenails often accompanied by fungal infections; second, atrophy of the extremity muscles, malnutrition, poor muscle tone, and susceptibility to injury in joints and ligaments; third, visible sinking of the finger joints, joint bending, weakening or disappearance of foot deformities, and cool, swollen skin at the extremities; fourth, patients often experience extremity pain, numbness, sensory abnormalities, and dull or absent deep and superficial reflexes. In the initial stages of diabetic foot gangrene, blistering, blood blisters, erosion, and infection can gradually develop into ulcers, gangrene, or necrosis. Clinically, this is manifested as localized redness, swelling, increased skin temperature, pain, functional impairment, and the presence of purulent secretions, sometimes accompanied by a foul odor.