Gastric cancer is a systemic disease, and only those tumor cells that have already “germinated” and “grown” can be removed by surgery, but often there are still cancer cells that have just taken root and have not had time to grow or are still dormant. However, often there are still cancer cells that have just taken root and have not yet had time to grow or are still in a dormant state. Once the conditions are ripe, these tiny metastatic foci will become the trigger for recurrence and metastasis after surgery. Therefore, gastric cancer patients should insist on a certain course of chemotherapy after surgery, firstly, to consolidate the efficacy of surgery, and secondly, to remove the “residual force” of cancer cells, so as to effectively prevent recurrence and metastasis of gastric cancer after surgery. At present, the five-year survival rate of gastric cancer patients in China is about 40%, but not every gastric cancer patient can get a longer survival period, and the threat of cancer recurrence will still jeopardize their lives.