Malignant thoracic and abdominal effusion is one of the common complications in the late stage of malignant tumor. Malignant body fluid is a common complication for patients with advanced tumor, among which malignant abdominal effusion accounts for about 60%, caused by abdominal metastasis of gastric cancer, colorectal cancer, hepatocellular cancer and ovarian cancer as the most common. It not only worsens the condition, but also seriously affects the survival quality of patients. Treatment methods are mostly based on local simple fluid extraction plus single drug chemotherapy, which has limited effect and ascites is prone to recurrence. Despite the limited survival of patients with advanced tumors, successful palliative treatment to reduce ascites production and alleviate the pain caused by abdominal pain has a positive effect on the quality of survival and prognosis of patients. Body cavity thermal perfusion therapy machine is the latest and organic combination of heat therapy and chemotherapy, which mainly targets cancerous effusion in body cavity and realizes a comprehensive body cavity thermal physical therapy. Based on the characteristic of apoptosis of cancer cells at 42-43.5℃, the therapeutic fluid and/or fluid circulation perfusion is used to kill cancer cells in the body cavity by controlling the temperature of the perfusion fluid within the proposed threshold, and to achieve effective killing of cancer cells in the body cavity; at the same time, the heating can increase the permeability of peritoneum and the cytotoxic effect of chemotherapeutic drugs, thus improving the efficacy of chemotherapy. This comprehensive therapy has curbed the problem of “reflux” of cancerous fluid and successfully solved the problems of traditional intracavitary irrigation, unconstant flushing temperature, unbalanced body cavity temperature, complicated operation, need for surgery and anesthesia, and high incidence of abdominal pain. The concentration of intra-abdominal drugs in the intra-abdominal cavity is 2.5-8 times higher than the plasma concentration within a few hours of intra-abdominal chemotherapy administration, which can form a constant, long-lasting and highly concentrated anti-cancer drug environment in the abdominal cavity, portal vein and liver, while the amount of drugs entering the body circulation is very small. Compared with traditional intravenous chemotherapy, intraperitoneal drug delivery not only improves the concentration of intraperitoneal anti-cancer drugs and prolongs the contact time between drugs and cancer cells, but also plays a stronger role in killing cancer clots and cancer cells metastasized to the liver via portal vein because intraperitoneal drugs are mainly absorbed through portal vein. Intraperitoneal thermoperfusion chemotherapy is designed according to the anatomical structural characteristics of the abdominal cavity, the rationality and effectiveness of regional chemotherapy pharmacokinetics and the principle that thermotherapy combined with chemotherapy has a synergistic anti-cancer effect. Tumor tissues are more sensitive to heat than normal tissues, and heating has a direct killing effect on cancer cells, and maintaining the temperature above 42℃ for 50-60min has a significant inactivating effect on malignant tumors. High temperature increases the drug concentration in local tumor tissues, and the high concentration of chemotherapeutic drugs can overcome the drug resistance of tumor cells, so as to better play the anti-cancer effect. Heating can improve the sensitivity of tumor cells to certain chemotherapeutic drugs, while cell permeability is enhanced, and changes in tumor cell microenvironment and pharmacokinetics strengthen the effect of anticancer drugs. Warm fluid can increase the permeability of anticancer drugs with direct penetration depth up to 5 mm, which can enhance the cytotoxic effect of chemotherapeutic drugs, induce apoptosis of tumor cells and enhance the killing effect on cancer cells. The efficiency of body cavity thermal perfusion is significantly higher than that of simple abdominal thermal chemotherapy group, and the toxic and side effects are similar, indicating that continuous thermostatic circulating chemotherapy is one of the more effective methods for treating cancerous ascites.