Enlarged abdominal lymph nodes in children are mainly caused by infection, allergy, hematologic diseases, and lymph node metastasis of malignant tumors, as follows: First, infection: it may be caused by bacterial infection, such as acute appendicitis, or by bacterial infection in the intestine. This may be caused by bacterial infection, such as acute appendicitis, or bacterial infection in the intestinal tract. In this case, it is necessary to improve the relevant examination, such as blood count, C-reactive protein, ultrasound, etc. Generally, it is necessary to give antibiotics for treatment. It may also be caused by viral infections, such as respiratory infections, which need to be treated with antiviral drugs, and hot compresses can be applied to the abdomen to help relieve the symptoms. Secondly, allergic factors, blood system diseases, etc.: for example, lymphoma, etc. Thirdly, lymph node metastasis of malignant tumor: it is necessary to improve other examinations, such as abdominal CT, tumor markers, colonoscopy and other examinations.