Laparoscopic-endoscopic cooperative surgery (LECS) has gradually emerged as an important surgical modality in the precise surgical management of gastric cancer. Through the intraoperative synergy of gastroscopy and laparoscopy, LECS provides a reliable technical solution for minimally invasive surgery of complex gastric cancer, effectively enhancing the accuracy of intraoperative margin assessment and addressing clinical challenges such as ambiguous tumor boundaries. Adenocarcinoma of the esophagogastric junction, due to its unique anatomical location and complex lymphatic drainage pathways, carries a relatively high risk of positive surgical margins, thereby imposing more stringent requirements on intraoperative precise localization and margin control. A standard of 3 cm for the proximal resection margin and 4 cm for the distal resection margin is recommended as standards for intraoperative margin management to minimize the incidence of positive margins. A standardized operational workflow comprising “preoperative titanium clip marking and localization - intraoperative dual-scope collaborative confirmation - methylene blue margin marking - precise measurement with a dedicated laparoscopic rod ruler” provides a referable technical pathway and standardized operational framework for the precise implementation and safety assurance of minimally invasive gastric cancer surgery. Nevertheless, the clinical application of LECS still encounters numerous technical difficulties. These challenges can be effectively addressed through the establishment of standardized operational protocols, training surgeons to independently perform endoscopic procedures, appropriately extending the safe margin distance for high-risk pathological types, and reinforcing intraoperative frozen pathological screening. Currently, clinical research on the application of dual-scope combined technology for intraoperative tumor localization and margin assessment in gastric cancer remains relatively scarce, with most studies being single-center or retrospective in design. Future endeavors should focus on conducting more large-scale, multicenter, prospective studies to provide higher-level evidence-based medical evidence.