Psoriasis, commonly known as “psoriasis”. It is a common chronic recurrent inflammatory skin disease. It is difficult to treat and has a prolonged course, making it one of the most persistent diseases in dermatology. The photophysical therapy (UVB therapy) for this disease has been widely used in hospitals nationwide as the first-line adjuvant treatment for psoriasis internationally. UVB treatment has very strict requirements on the dose and time of irradiation, and any irregular irradiation may lead to treatment failure. Therefore, it is not possible to change or terminate the treatment on your own during the course of treatment. Before each UVB treatment, it is necessary to bathe the whole body, remove scales as much as possible, and perform medicated bath treatment if necessary to enhance the absorption and utilization of drugs and light. During the irradiation process, the distance between the treatment site and the irradiation reflector should be kept constant, and the distance between the irradiation site and the lamp should be greater than or equal to 4cm to avoid burns. During UVB treatment, please avoid taking and using photosensitive substances to avoid photosensitive reactions on the skin. Photosensitizing substances include food, western medicine, Chinese medicine and daily necessities. Food: mud snail, ashwagandha, chard, capers, rape, spinach, lettuce, citrus, fungus, laxative tea, etc. Western medicine: sulfonamide, hypoglycemic drugs, tetracycline, ashwagandha, diuretics, Valium, salicylates, oral contraceptives, etc. Chinese medicine: bone fungus, dahurica, cumin, etc. Daily necessities: cosmetics containing fragrances, shower gel, etc. In addition, on the day of photophysical treatment, care should be taken to avoid sun exposure to avoid aggravating the skin reaction. This is especially likely in summer. After UVB treatment, topical emollient preparations should be routinely applied to avoid itching and discomfort due to the loss of moisture in the skin after phototherapy. Of course, in the standardized UVB treatment of psoriasis, how many times do we need to shine to achieve a more satisfactory clinical effect, and whether the time interval of each treatment is the same, etc. will be mentioned in future articles.