An optimal delimitation of basic farmland needs to consider the food security and cultivated land quality in modern agriculture. Taking Zhecheng County, Henan Province of China as an example, this study aims to determine an optimal construction space of basic farmland from bottom to top, considering national food security and population development. The specific procedure was: 1) A combined gray-BP network model was adopted to predict the population and cultivated land demand in the study area from 1999 to 2025; 2) The population from 1999 to 2025 was used to calculate the food demand and security rate via a specific conversion. Six major ways of food consumption were selected to analyze the capacity for food security of the County; 3) An evaluation system of farmland quality was established to select the indicators from production conditions, location, landscape, and policy conditions. A quantitative analysis was performed on the indicators with geographic information technology and weighted index summation model for comprehensive quality scores of cultivated land; 4) A specific planning of construction land was proposed to fully integrate the quality evaluation of cultivated land into the current food security expectations and cultivated land demand. Consequently, the cultivated land was divided into the Food Security Protection Zone, Food Security Buffer Zone, Town Development Planning Zone, and Comprehensive Land Improvement Zone. The results indicated: 1) The County was in food-shortage from 1990 to 2005, but in food surplus from 2005 to 2019. Although food security was generally achieved, the risk of "hidden hunger" still existed from the perspective of food consumption structure; 2) The comprehensive quality score of cultivated land ranged from 29.57 to 92.87, with an average value of 59.53, indicating relatively good comprehensive quality. 3) The cultivated land quality in the food security protection zone was relatively high, where it was recommended to be included into the basic farmland. Meanwhile, the cultivated land quality in the Food Security Buffer Zone was relatively weak but with single limited factors, where it was advised to be also included into the basic farmland that required short-term land consolidation for the better quality of cultivated land. Given that the Town Development Planning Zone surrounded the town center in a ring layout and quality of cultivated land, it was suggested to be used for urban construction land. The direction of urban development was addressed to prevent the destruction of high-quality cultivated land. The comprehensive land improvement zone was taken as an alternative area for basic farmland, due to the scattered spatial distribution and weak land quality. It also needs to identify the obstacle factors for better land productivity using long-term comprehensive land remediation. These recommendations can make a great contribution to the protection of cultivated land, urban development, and comprehensive land consolidation. The integrated delimitation of basic farmland with food security can avoid the drawbacks of simplex delimitation in the dynamic evolution of basic farmland delimitation. The finding can provide a sound technical reference to the long-term stability of national food security and revitalization of cultivated land resources.