Proximal early gastric cancer can choose radical total gastrectomy or proximal gastrectomy. The patients have poor nutritional status and quality of life after total gastrectomy. Compare to total gastrectomy, the nutritional status can improve after proximal gastrectomy . But if use simple esophagogastric anastomosis for proximal gastrectomy, the incidence of postoperative reflux esophagitis is high, which seriously affects the quality of life, and the short-term outcome is poorer than the total gastrectomy. If the incidence of postoperative reflux esophagitis can be reduced, proximal gastrectomy would be the treatment choice for proximal early gastric cancer, which may more improve both quality of life and nutritional condition than total gastrectomy. Double-flap technique is a new surgical reconstruction procedure between esophagus and remnant stomach. It can reduce the occurrence of reflux oesophagitis through reconstruction a simulative cardia. At present, the technique has been carried out in some hospitals in China but still lack large-scale prospective studies and evidence of evidence-based medicine. At present, some retrospective studies have shown that robotic assisted proximal gastrectomy with double-flap technique is safe and effective, and the learning curve is shorter than laparoscopic surgery. The applicant have finished two robotic assisted proximal gastrectomy with double-flap technique cases. Two patients recovered well after surgery, with no occurrence of anastomotic leakage or stenosis and the postoperative quality of life was good. Now we plan to conduct a multi-center, single arm study on proximal early gastric cancer patients(T1N0-1M0 and T2N0M0) to evaluate the feasibility of robotic assisted proximal gastrectomy with double-flap technique , and to evaluate the surgical and oncological safety of this surgical method. Aim to provide initial evidence of evidence-based medicine for its clinical application..