R0 resection of gastric cancer is the ideal state for radical surgery of gastric cancer. It is a complete resection of about 5cm around the lesion, so that there is no tumor residue visible to the naked eye or under the microscope. It is mostly seen in early stage gastric cancer patients who have the chance of surgery, and the 5-year survival rate is relatively high after timely radiotherapy and regular review. Therefore, it is very necessary to have regular physical checkups, such as stomach discomfort, acid reflux, heartburn, stomach pain, etc., and timely hospital consultation and gastroscopy if necessary, so as to achieve early detection, early diagnosis, early treatment and early gastric cancer resection. In addition to R0, there are some patients who cannot undergo radical surgery, such as R1 with residual cut edges visible under microscope and R2 with residual cut edges visible to the naked eye but no distant lesions. the healing of gastric cancer surgery R1 and R2 is relatively worse than R0.