Lymphocentesis, i.e., puncture biopsy of lymph nodes, can clarify the cause of enlarged lymph nodes, such as infection, tuberculosis and tumor. Lymph nodes are distributed in all parts of the body and can filter lymphatic fluid, remove bacteria and foreign bodies, as well as produce lymphocytes and antibodies, etc. They are important immune organs of the body. When infection occurs in local tissues, pathogens or toxins can enter into the lymph nodes along with lymphatic channels. After perfect lymphatic puncture, pathogenic microorganisms such as bacteria, viruses, fungi or parasites can be found, which can help in the diagnosis of the disease. When Mycobacterium tuberculosis invades the lymph nodes, it can cause lymphatic tuberculosis, resulting in enlarged lymph nodes, and the diagnosis can be clarified after perfecting lymphatic puncture biopsy and pathologic examination. When lymphocytes become cancerous or tumors from other parts of the body metastasize to the lymph nodes, it can be manifested as enlarged lymph nodes, i.e. lymphoma or lymphatic metastasis, which can be clearly diagnosed after perfecting lymphocentesis biopsy and pathological examination. Lymphatic puncture needs to be operated by specialized doctors, and after the examination clarifies the cause of the disease, the treatment should be in accordance with the doctor’s prescription.