Immunotherapy can be used to treat flat warts, and the results are generally better, but the treatment may vary due to individual differences. The immunotherapy of flat warts is to implant the autologous warts into the subcutaneous fat tissue through surgery or other means, so that the body produces antigens, which will stimulate the body’s immune system, so that the body produces effective antibodies, forming a specific immune response, and then clearing the human papillomavirus, belonging to a kind of active immunotherapy, which can enhance the function of the immune cells, and the side effects will be relatively small. When the patient is treated with immunotherapy, there may be transient symptoms of local redness and itching, and then the warts can gradually fall off within 1~3 months, but due to individual differences, the situation of flat warts may vary. During the immunotherapy treatment, patients should keep their skin hygienic and clean, and can also use topical medications such as retinoic acid ointment, imiquimod cream, and fluorouracil ointment with the doctor’s advice. It is recommended that patients go to the hospital in time, under the guidance of the doctor according to the patient’s condition to choose immunotherapy, and operated by professional doctors, the use of drugs need to follow the doctor’s instructions.