The research of resources and environmental carrying capacity is an important basic work in China’s national land use planning and rural revitalization planning. Current research on resources and environmental carrying capacity remains at large regional scale, and the evaluation of carrying capacity for villages and towns is relatively uncommon. Based on a summary of previous research, this study explored the evaluation method of resources and environmental carrying capacity for villages and towns at the county scale on the basis of the “dual evaluation” technical guideline of the National Land and Spatial Planning published by the Ministry of Natural Resources. Yongfeng County of Jiangxi Province, which is located in the hilly area south of the Yangtze River, with a total population of 44×104 in 2017, was taken as an example. Based on the preliminary evaluation of the characteristics of the village and town development in Yongfeng County and the resources and environmental constraints, the index system for determining the unsuitable areas for cropping and village and town development with land, geological hazards, and ecology as the main limiting factors was established, and administrative villages were classified. Appropriate types of village and town development for village units and optimal population size of the county were determined under two scenarios of high development intensity and average development intensity. The results of the study show that the areas unsuitable for cropping and village and town development in Yongfeng County were 1797.77 km2and 1838.68 km2, respectively, which is 1838.94 km2 excluding the overlapping area, accounting for 67.81% of the county area. According to the unsuitable area, current population, and village and town development level, the 216 administrative villages in the county can be divided into four major categories: ecological protection key villages, cropping development key villages, central key villages, and other villages. Under the scenarios of local high development intensity and average development intensity, the largest population that the county’s arable land and planting industry can support will be 135.38×104 and 140.10×104, respectively. Assuming 100 m2, 140 m2, and 200 m2 per capita construction land, under the high-intensity development scenario, the number of population that can be supported by villages and towns in the county will be 84.05×104, 60.04×104, and 42.03×104 respectively; under the average development intensity scenario, the population size will be 54.61×104, 39.01×104, and 27.31×104 respectively. The results of this research can provide a case for the current “dual evaluation” technical guideline, and provide a reference for the implementation of rural revitalization and village and town planning in Yongfeng County.