Psoriasis is a common erythematous scaling skin disease with a genetic background and associated with abnormal immune response. Clinical manifestations are red papules or well-defined plaques covered with silvery white scales; skin damage can be limited or generalized; in addition, joints, nails and mucous membranes can be involved; a few cases of non-common psoriasis are characterized by pustules, arthritis and erythroderma. Most of the disease is chronic, easy to recur, and there is no curative therapy. I. Etiology and pathogenesis of psoriasis The etiology of psoriasis is not yet completely clear, but some causative factors or susceptibility factors are clear. Psoriasis has a genetic background and can be triggered or aggravated by internal and external environments such as trauma, infection, drugs, combined diseases, smoking and mental trauma. It is now believed that psoriasis is an autoimmune disease mediated by T-lymphocytes in a polygenic genetic background. Patients have abnormal functions of various immune cells, immune molecules and intracellular signaling systems. The application of molecular biology technology can effectively control the occurrence and development of psoriasis to a certain extent by blocking the functions performed by multiple factors in the effector phase of lymphocytes through specific antibodies. Second, psoriasis patients’ precautions 1, dietary precautions Psoriasis patients advocate food diversification, for health care, to obtain the various nutrients needed by the body, must be obtained from a variety of foods, food diversification in line with the principles of nutrition, partial food, taboos and gluttony are not conducive to general health, the same is also not conducive to psoriasis recovery. In fact, many patients used to avoid eating but did not achieve the purpose of recovering from the disease or preventing relapse. As a large amount of scales are shed and much protein is lost, it is important to pay attention to protein intake and add 1-2 eggs to the daily diet to replenish the lost protein. At present, the clear food that psoriasis patients cannot consume is beef and mutton. 2.Cautions for daily life It is important for patients to pay attention to the combination of work and rest and to maintain a good mental state. As we all know, a good mental state is an important factor in maintaining health. For psoriasis, a positive, optimistic and cheerful mental state is conducive to the recovery of the disease. On the contrary, mental stimulation, excessive emotional tension or anxiety can often trigger the occurrence of psoriasis or aggravate the condition. There are numerous examples of this. It is also important to enhance physical fitness, avoid cold, prevent colds, prevent infectious diseases such as tonsillitis, and avoid trauma, as some patients may be triggered by these factors.