Confirmation of the diagnosis of dermatologic diseases mainly rely on typical clinical symptoms, some diseases need auxiliary examination to confirm the diagnosis, such as pathologic examination, imaging, laboratory diagnostic methods. 1. Skin histological examination: such as the diagnosis of skin tumors, specific changes in certain viral diseases, identification of similar diseases such as connective tissue disease, granulomatous dermatosis and other specific pathological changes can be well identified with other diseases. 2. Skin imaging: skin CT, dermoscopy, etc., dermoscopy is mainly used for inflammatory skin diseases, pigmented diseases, nail disease and hair, etc., but the skin reflection confocal microscopy than dermoscopy to detect a wider range. 3. Laboratory diagnostic methods: such as immunohistochemistry is mainly used in connective tissue disease, direct smear is mainly used for fungal examination, and the examination of venereal disease is mainly for different pathogens to choose different ways. 4. Other: allergen monitoring such as patch test is mainly used for contact dermatitis, cosmetic dermatitis, etc., prick test is mainly used for urticaria, atopic dermatitis and so on. Different skin diseases choose different ways of examination should go to the hospital in a timely manner, in the judgment of the professional physician to choose the appropriate way of examination, maximize the savings of resources, and timely treatment for the disease.