The causes of ascites after surgery are hypoproteinemia, intra-abdominal infection, and secondary peritonitis. 1. Hypoproteinemia: a lot of ascites after surgery may be due to the patient’s poor nutritional status after surgery, resulting in hypoproteinemia, which reduces the plasma colloid osmotic pressure, thus leading to the formation of ascites. Patients can improve the treatment by inputting parenteral or enteral nutritional solution, intravenous infusion of albumin and so on. Diuretics can also be injected appropriately to promote absorption. 2. Intra-abdominal infection: patients may also suffer from intra-abdominal infection after surgery, causing infectious peritonitis, leading to more inflammatory secretions leaking out and causing ascites. Patients can be treated with intravenous ceftriaxone sodium, levofloxacin and other antibiotics to eliminate the infection and reduce the production of ascites. If necessary, surgery again. 3. Secondary peritonitis: the patient has been a lot of ascites after surgery may also be related to secondary peritonitis, mainly manifested as abdominal pain, malignant, ascites and other symptoms. To actively carry out anti-infection treatment, usually pay attention to choose the semi-recumbent position to prevent the occurrence of drainage and so on. There have been many cases of ascites after surgery, such as residual tumor tissue, impaired liver function and so on. It is recommended that patients seek medical treatment in time to identify the cause of the disease, so as not to delay the condition.