Gastric cancer is a common malignant tumor of the upper gastrointestinal tract, and metastasis includes lymph node metastasis and bloodstream metastasis. Lymph node metastasis is the main metastasis mode of gastric cancer, and the common metastasis sites are the lymph nodes in the abdominal cavity, next to the left gastric artery and next to the abdominal cavernous artery, and some of them are prone to metastasis to the lesser curvature of the stomach. In addition, tumors of the digestive tract, especially gastric cancer, are also prone to somatic metastasis, most commonly to the left supraclavicular lymph node, because the lymphatic fluid of the digestive tract flows back into the left venous angle. In addition, many patients may also develop retroperitoneal lymph node metastasis, which may manifest as abdominal distension, abdominal pain, and also affect the bowel function or develop unexplained diarrhea. Since there is a nerve plexus behind the peritoneum, the metastasis of lymph nodes may also compress the local nerve plexus and cause uncontrollable pain. For patients with gastric cancer, pain relief treatment can be chosen if there is plexus invasion.