Thymopentin, as an immunomodulator, can be used to treat skin diseases and is an adjuvant rather than a primary medication. In the treatment, it can be applied to skin diseases caused by reduced immunity or skin diseases caused by immune disorders. Skin diseases caused by reduced immunity include dermatoses, herpes zoster, boils and other bacterial and viral infections. Besides, it can also treat skin diseases caused by immune disorders, such as eczema, contact dermatitis, and urticaria. Besides treatment with thymopentin, there are also transfer factors, thymopeptide enteric capsules, mushroom mushroom polysaccharide tablets, pidomod oral solution and even intramuscular injection of BCG polysaccharide for the treatment of skin diseases routinely.