Dry gangrene is mostly seen at the ends of the extremities in diseases such as atherosclerosis, thrombo-occlusive vasculitis and frostbite. At this time, arterial obstruction and venous return flow, so the necrotic tissue is less water, coupled with easy evaporation of water from the body surface, resulting in a dry and crumpled lesion, dark brown, and a clear demarcation line between the surrounding healthy tissue. Because the necrotic tissue is relatively dry, the infection by spoilage bacteria is generally light. So, how to prevent dry gangrene? First, primary prevention: 1, free from indoor too cold or too hot, the temperature should be appropriate. 2, prevention of infection, enhance physical fitness, improve their own immune function, regular life, and relaxed mood. 3, strong nutrition, avoid smoking, alcohol and spicy stimulating items, also avoid fatty, sweet and thick products. Secondary prevention: 1.Early diagnosis. 2, early comprehensive treatment.