Malignant thoracoabdominal fluid is often seen in advanced malignant tumors, especially in lung, stomach, colorectal and ovarian cancers, and the effect of conventional intracavitary chemotherapy is not good. In January 2008, the Department of Oncology carried out intra-thoracic and intra-abdominal thermal perfusion chemotherapy, which has achieved very good results. Heat chemotherapy is beneficial for chemotherapeutic drugs to enter tumor cells: 1. High temperature increases the fluidity of tumor cell membrane and the permeability of tumor blood vessels, which increases the entry and accumulation of chemotherapeutic drugs in tumor cells and enhances the anti-tumor effect of chemotherapeutic drugs. 2.Heat therapy can eliminate the regulatory power of certain oncogenes on the uptake and excretion of chemotherapeutic drugs by cells, so that the excretion of chemotherapeutic drugs in tumor cells will be reduced and the accumulation will be increased. 3.Heat can reduce the interstitial hydraulic pressure of tumor tissues and promote the transport of anti-cancer drugs. 4.The synergistic effect of thermal chemotherapy can kill the tumor cells in resting state in tumor tissue. Intrathoracic perfusion of chemotherapeutic drugs can achieve higher drug concentration in the cavity and enhance the direct cytotoxic effect on cancer cells. With the advantages of both intracavitary heating and intracavitary perfusion of chemotherapeutic drugs, the two exert synergistic antitumor effects. The warming effect can induce changes in the ultrastructure of tumor cell membranes, improve the ability of cell membranes to operate and take up chemotherapeutic drugs, and disrupt the metabolic process of tumor cells, thus promoting the cytotoxic effects of chemotherapeutic drugs. Intracavitary irrigation also helps to mechanically flush out the cancer cells shed in the free lumen and reduce the chance of cancer cell implantation and metastasis. The effect of thermal perfusion chemotherapy is significantly higher than the sum of heat therapy alone and chemotherapy alone, which has significant synergistic effect, thus significantly reducing the dose of chemotherapy drugs and reducing the toxic side effects of chemotherapy drugs on the basis of achieving the best efficacy of chemotherapy drugs. The recent effective rate is over 90%.