China’s rapid income growth and urbanization have led to significant changes in food consumption patterns, and these dietary changes may increase the demand for agricultural land for food supply. This study explores the changes in urban and rural residents’ cropland demand based on dietary data of Chinese residents from 1990 to 2020, using dietary nutritional analysis and a cropland footprint method. The results show that during the study period, the total cropland demand of rural residents decreased by 31.02%, from 61.31 million hm2 to 42.29 million hm2, while the total cropland demand of urban residents increased by 246.83%, from 22.91 million hm2 to 79.46 million hm2. The results reveal that the primary drivers of increased cropland demand are urbanization and rising animal-based dietary patterns. However, the contribution of increased agricultural productivity to decreased demand for cropland is relatively small and inadequate to compensate for the increased demand. In short, the pressure to protect arable land in China will continue to rise, and protecting existing arable land, improving cropland productivity, and making full use of international resources are the main ways to alleviate the pressure on arable land protection.