Stomach cancer with peritoneal metastasis is an advanced condition, and the survival period of this condition is about six months to one year. Meanwhile, active treatment is needed, and if the treatment is not effective, the survival period is only about three months. The main symptoms of peritoneal metastasis of gastric cancer are abdominal pain, abdominal distension and fluid accumulation in the abdominal cavity, and serious intestinal obstruction and intestinal adhesions may occur. When peritoneal metastasis occurs in gastric cancer, it mainly requires systemic chemotherapy treatment. Secondly, abdominal drainage tube should be placed for peritoneal fluid accumulation. After the ascites is controlled, intra-abdominal injection of chemotherapy and immunological agents can be used to control the growth of lesions and ascites in the abdominal cavity, so as to better improve the quality of life and prolong the survival time of patients.