Abstract: This study aims to optimize the land use spatial pattern in the major agricultural production areas at the county level, in order implement the national functional zoning and food security. An optimization framework was constructed for the land use spatial pattern of major agricultural production areas, according to the four aspects of "scale-structure-layout-strategy." Taking Qixian County in Shanxi Province as an example, the optimization targets were defined as the food security, ecological security, economic development, carbon reduction, and social security. The grey multi-objective model was coupled with the GeoSOS-FLUS model. The county was further divided into the functional zones. The development strategies were proposed for each zone. The results were as follows: 1) The area of arable land was remained at 38,320.60 hm² by 2035 after structural optimization; The area of forest land increased to 17,172.40 hm², in order to enhance the carbon sequestration; Grassland decreased to 21,485.80 hm² for the optimal land use; The water area increased to 159.50 hm² for the ecological services; The construction land was expanded to 8,214.70 hm². The total economic output was predicted to increase by 1,097,676 million yuan, compared with 2021. Net carbon emissions were reduced by approximately 239,200 t, compared with the natural development trend, and 86,250 t, compared with 2021. Carbon intensity was predicted to decrease by 53.34%, compared with 2021, and by 88.57% compared with 2005. These predictions were achieved in the multiple objectives from the agricultural production, ecological protection, and economic development. 2) The GeoSOS-FLUS model was used to simulate the layout of land use. The Kappa index reached 0.87, with an overall accuracy of 0.91, indicating the high precision and reliable optimization. Furthermore, the more concentrated and efficient forest land was significantly improved the carbon sequestration; The quality of arable land was enhanced to further ensure the national food security. More concentrated construction land was also promoted the economic circulation. The optimized layout provided a solid spatial foundation for the sustainable development in major agricultural production areas. 3) According the development potential of different townships, the county was divided into three zones: agricultural production, economic development, and carbon sequestration. Among them, the carbon sequestration zone aimed to enhance the carbon sequestration and protect ecosystems. The ecological corridors and projects were dominated, such as returning farmland to forest, grassland protection, and wetland restoration, particularly for the low-carbon tourism and ecological agriculture. The economic development zone aimed to promote the industry clusters and infrastructure. The industrial restructure and carbon reduction were then driven to enhance the connectivity with the Taiyuan metropolitan area. The agricultural production zone prioritized the protection and quality of basic farmland and the arable land. Characteristic agriculture was developed to promote the branding of Qixian pear. Green and low-carbon agriculture was implemented to construct the modern agricultural industrial parks and rural infrastructure. The land use spatial pattern was also optimized in the major agricultural production areas at the county level. The county functional zoning and multidimensional development were integrated to coordinate the multiple objectives, such as food security, economic development, carbon reduction, ecological security, and social security. The differentiated strategies were proposed to formulate the land use and territorial spatial planning. The spatial optimization of land use can offer the valuable insights to the functional counties for the agricultural modernization and the carbon neutrality.