The treatment paradigm for early gastric cancer (EGC) is shifting from extended radical resection toward minimally invasive, precise, and function-preserving approaches. Sentinel lymph node (SN) navigation, laparoscopic endoscopic cooperative surgery (LECS), and robotic endoscopic cooperative surgery (RECS) provide new strategies for local gastric resection, regional lymphadenectomy, and functional preservation. For indocyanine green (ICG) injection, intraoperative endoscopic submucosal direct injection is recommended, with a maximum volume of 1.0 mL per site, following the principle of “shallower rather than deeper,” injecting slowly and observing submucosal elevation to confirm successful delivery. Preoperative workup for LECS and RECS includes magnifying chromoendoscopy to rule out synchronous lesions, endoscopic ultrasonography for T staging, and contrast-enhanced CT to assess lymph node metastasis. Intraoperatively, frozen section pathology of the SN determines whether to proceed with local resection or D2 gastrectomy; positive margins warrant additional extended resection, and invasion beyond T1b stage requires conversion to D2 gastrectomy. Postoperatively, endoscopy is performed to check for suture defects, and a jejunal feeding tube is placed. This protocol constitutes a systematic procedure for function- preserving EGC surgery, aiming to maximize gastric preservation while ensuring oncological radicality and improving patients’ long-term postoperative quality of life.