Stage I gastric cancer is treated according to the stage, radical surgery first, with postoperative chemotherapy for those with high-risk factors; stage II radical surgery first, with postoperative adjuvant chemotherapy; stage III gastric cancer is operated as far as possible, and patients with difficulties in surgical resection adopt the treatment strategy of chemotherapy first, then surgery, and postoperative adjuvant chemotherapy; and stage IV stage is based on the integrated treatment of chemotherapy, targeting, immunotherapy, and other therapies. 1. Stage I gastric cancer excludes contraindications to surgery and radical surgery is preferred. Patients with high risk factors for recurrence and metastasis need postoperative adjuvant chemotherapy, and the high risk factors include high malignancy, incomplete lymph node dissection, vascular tumor embolism, indolent cell carcinoma, and age less than 50 years old. 2. Stage II patients adopt the comprehensive treatment strategy of radical surgery combined with postoperative adjuvant chemotherapy. 3. If stage III patients can be radically resected, they should try to undergo surgery first, followed by postoperative adjuvant chemotherapy. If the tumor is large and radical resection is difficult, chemotherapy can be used to shrink the tumor first, followed by radical surgery and postoperative adjuvant chemotherapy. 4. According to the different factors such as gene expression and immune status, stage IV patients can adopt comprehensive treatment measures such as chemotherapy combined with targeting or combined with immunotherapy.