Children’s constant recurrent fever can be caused by infections, but also seen in non-infectious diseases such as hyperthyroidism, systemic lupus erythematosus and leukemia. Infectious fever is mostly seen in respiratory tract infections, and the pathogens include bacteria, viruses, mycoplasma, tuberculosis and so on. If the infection is not controlled or the autoimmunity is low, recurrent fever will occur. In addition, recurrent fever can also be seen in other non-infectious diseases, such as hyperthyroidism, systemic lupus erythematosus, Kawasaki disease, dermatomyositis, leukemia, and chronic non-specific lymphocytosis. It is recommended to consult a doctor in time to clarify the cause of the disease and then carry out regular treatment.