According to the Chinese medicine industry standard of the People’s Republic of China, the diagnostic criteria for psoriasis are: 1. The skin lesions are initially inflammatory red papules from the size of a needle tip to a lentil, often with a dotted distribution, rapidly increasing in size, and covered with silvery white multilayered scales, like mica. After the scales are peeled off, the film phenomenon and sieve hemorrhage can be seen, the base is infiltrated, and there can be isomorphic reaction. The old rash can be coin-shaped, disc-shaped, map-shaped, etc. 2. The rash is usually found on the scalp, extensor side of the extremities, more often on the elbow joint surface, and often generalized to the whole body. 3, some patients can see nail lesions, the lighter the dotted depression, the heavier the nail plate thickening, luster disappeared. It may be seen in the oral cavity and mucous membrane of the pubic area. If it occurs on the scalp, bundles of hair can be seen. 4. Slow onset, easy to recur. There are obvious seasonality, generally heavy in winter and light in summer. 5. There may be a family history. 6. Histopathological examination shows hyperkeratosis and underkeratosis of the epidermis. There is an accumulation of neutrophilic polymorphonuclear leukocytes in the stratum corneum and thickening of the spinous layer. The epidermal protrusions are regularly extended downward, the dermal papillae are edematous and rod-shaped, the blood vessels within the papillae are dilated, and there is inflammatory cell infiltration around the blood vessels.