Proximal early gastric cancer can choose radical total gastrectomy or proximal gastrectomy. But if use simple esophagogastric anastomosis for proximal gastrectomy, the incidence of postoperative reflux esophagitis is up to 62%, 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 status than total gastrectomy. Double-flap technique is a new surgical procedure for the reconstruction between esophagus and remnant stomach, which was started to be applied to digestive tract reconstruction in patients with proximal early gastric cancer in 2016. It can reduce the occurrence of reflux oesophagitis. At present, the studies for double-flap technique in China and other countries are mostly retrospective studies, and there are short of large-scale prospective studies and evidence of evidence-based medicine. The applicant has initiated a phase II, single center, single arm study and the results suggested that the laparoscopic proximal gastrectomy with double-flap reconstruction technique was safe and effective for treating proximal early gastric cancer. To further validate the short and long-term outcomes of this procedure, a multicentre, open label, prospective, superiority and randomised controlled clinical trial was set up to compare laparoscopic proximal gastrectomy with double-flap technique with laparoscopic total gastrectomy with Roux-en-Y reconstruction for proximal early gastric cancer. It include 216 patients with proximal early gastric cancer. The primary outcome is the proportion of patients who develop reflux esophagitis within 12 months after surgery. The short and long-term oncological outcomes are also explored. This trial can provide high-grade evidence of evidence-based medicine for double-flap technique's clinical applications .