Abstract:The “ Greater Food" approach provides a holistic and systematic perspective for exploring the in-trinsic connections between agricultural production and food consumption. From this perspective, megacities arecharacterized by strong consumer demand, limited supply capacity, complex distribution systems, and high re.quirements for grain reserves and emergency security. Balancing grain production capacity with allocation efi.ciency, integrating grain reserve security with emergency response, and unilying grain quality and safety man-agement with risk prevention are essential for ensuring food security in megacities. To this end, this study takesChengdu as an example and analyzes the challenges faced by megacities, including intensified food supply anddemand contradictions, insufficient resilience of the food supply chain , prominent quality and safety risks, theurgent need to improve the emergency reserve system, and increased risks in the interational grain market. Tobetter ensure food security in megacities , it is necessary to empower grain production with technological innova.tion , build a moder agricultural supply chain system, guide residents to form scientific dietary habits, improvethe government-led grain reserve system, and conduct global grain trade based on domestic resources.