The criteria for confirming the diagnosis of peritoneal cancer is to perform biopsy pathology for diagnosis. Peritoneal cancer refers to malignant tumors occurring in the peritoneum, including primary peritoneal cancer and secondary peritoneal cancer. Secondary peritoneal cancer is due to metastasis from malignant tumors in other parts of the body, such as ovarian cancer and gastrointestinal tract tumors. Primary peritoneal cancer is a malignant transformation of cells of the reproductive duct system or gonadal cells commonly caused by carcinogens. Early symptoms of peritoneal cancer are atypical, which makes it difficult to confirm the diagnosis. As the disease progresses, symptoms such as abdominal distension, abdominal pain, lethargy and fatigue as well as anemia and edema may appear. To confirm the diagnosis of peritoneal cancer, cytology examination of ascites should be conducted to clarify the cytopathological diagnosis, and if cancer cells are found in ascites, it can be diagnosed as peritoneal cancer or peritoneal metastatic cancer. Tumor marker examination and imaging examination can also be performed. It is recommended to go to the hospital for diagnosis and active treatment.