Psoriasis is a common inflammatory skin disease with characteristic dermatophytosis, the medical name for psoriasis, that is chronic and easily recurring. Psoriasis begins as inflammatory red papules, about the size of a green pea, that gradually enlarge or fuse into brownish-red patches with well-defined borders. At the same time, it is surrounded by an inflammatory red halo, with marked basal infiltration and covered with multiple layers of grayish-white scales, which are gently scraped out to gradually reveal a large red translucent film, and then scraped away to reveal small bleeding spots. Psoriasis can be divided into three periods from its onset to its final fading, namely the progressive, quiescent and regressive phases. The current treatment of psoriasis is mainly according to mild, moderate and severe. Generally, if the area of dermatophytosis is less than 10% it is considered mild, and only topical medication is needed for mild, while both moderate and severe need to apply combined treatment. The topical medications include tar preparations, glucocorticoid and retinoid combination therapy, and the internal medications, which include a combination of antineoplastic drugs, retinoids and immunotherapy.