Abstract: Food security has always been the top priority of our national governance. As an extension of the concept of food security, big food concept has defined the direction for ensuring the supply of grain and other major agricultural products in the new development stage. The big food concept aims to meet the food consumption demand of “big market” , expand food sources by focusing on “big resources” , develop “big agriculture” to build a diversified food supply system. It follows the logic rules of ensuring national food security, satisfying food consumption upgrading, making full use of land resources and improving agricultural comprehensive benefits. In the new development stage, we can follow the idea of “transforming idea-enhancing ability-transforming behavior” and choose the practice path of big food from the social, policy and subject perspectives.