Acute cellulitis is an acute, diffuse, purulent infection of the subcutaneous, subfascial, intermuscular or deep loose connective tissue. Common pathogens are hemolytic streptococci and Staphylococcus aureus, and a few are caused by anaerobic bacteria and Escherichia coli. In recent years, with the development of microbiology and the improvement of detection methods, anaerobic infection and mixed infection have received widespread attention. Many studies have shown that anaerobic infection and mixed infection have a clear increasing trend. Cellulitis caused by Gram-negative bacteria is rare. The characteristics of this disease are: the skin of any part can be infected, and the lesions are not easy to be limited, spread rapidly, there is no obvious boundary between the lesion tissue and the normal tissue, and the symptoms of systemic poisoning are obvious. Therefore, while treating local infections, it is necessary to actively use antibiotics and take anti-shock measures in the early stage.