Portal space is the space between portal vein and inferior vena cava. Swollen lymph nodes in the hilar space after liver cancer surgery may be caused by postoperative infection or metastasis of cancer cells. 1. Postoperative infection: liver cancer surgery is traumatic to a certain extent, if it is not thoroughly sterilized before surgery or the related hygiene is not paid attention to after surgery, it may lead to infection and inflammation of the traumatic surface, causing inflammatory reaction, and the lymph nodes will be easily enlarged after being repeatedly stimulated by inflammation. 2. Cancer metastasis: after liver cancer surgery, cancer cells may easily metastasize or spread, and metastasize to the hilar space, resulting in enlarged lymph nodes. The swelling of lymph nodes in the hilar space after liver cancer surgery may be caused by the above factors. In order to clarify the cause of the disease, CT examination and ultrasound examination can be done for diagnosis and analysis, and once lymph node metastasis is detected, it is necessary to do lymph node dissection in a timely manner.