The causes of recurrent high fever in children are more, mostly seen in infection, rheumatic fever, tumor, blood system diseases, immunodeficiency diseases, etc. The common causes are analyzed as follows: 1. Infection, infection is one of the most common causes of pediatric fever, such as bacteria, viruses, tuberculosis bacillus, mycoplasma, etc. In addition to recurrent fever, the child may be accompanied by respiratory, gastrointestinal and other symptoms. 2. Rheumatic fever, which is a common rheumatic disease in children, mostly with fever for more than 5 days, invasion of the heart, erythema annulare, arthritis, etc. Cardiac ultrasound, blood test, etc., are needed to make a clear diagnosis. 3. Tumor, lymphoma, neuroblastoma, etc. are often accompanied by immune deficiency, which can be repeated over and over again, accompanied by malignant quality. 4. Blood system diseases, leukemia, hemophagocytic syndrome, etc., often with repeated fever, anemia, bleeding and other symptoms. 5. Immunodeficiency diseases, due to immunodeficiency, children often have recurrent infections that cause fever, which need to be clarified by checking immunoglobulin and so on. Children with repeated high fever, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.