Ascites after liver cancer surgery may be caused by large surgical trauma, spreading of cancer cells, liver injury, blockage of lymphatic system by cancer cells, high pressure in hepatic vein caused by cancer cells. 1. High surgical trauma: liver cancer surgery is more traumatic and prone to hypoproteinemia after surgery, which may lead to the formation of ascites. 2. Spreading of cancer cells: cancer cells spread to the abdominal cavity, prompting the collection of body fluids, thus producing ascites. 3. Liver injury: the synthesis of albumin decreases after liver injury, and the balance of body fluids is imbalanced, leading to ascites. 4. Cancer cells blocking the lymphatic system: lymphocytes are blocked by cancer cells, leading to obstruction of lymphatic return and ascites. 5. High pressure in hepatic vein caused by cancer cells: tumor cells cause elevated pressure in hepatic vein and blood can not enter the liver quickly, resulting in elevated pressure in the vein, which leads to the formation of ascites. Ascites after liver cancer surgery may also be caused by other reasons, which should be consulted in the hospital in time, and the specific treatment should follow the doctor’s instruction depending on the specific situation to avoid adverse consequences.