Empowered by breakthroughs in hybrid potato breeding technology and the well-established molecular design breeding in rice cultivation, we propose a new eco-circular agricultural model, referred to as "rice-potato-pig (RPP)". This model involves planting rice in spring and summer, growing potatoes in winter, and using potatoes and bran as feed for pigs, while simultaneously utilizing pig manure and urine to fertilize the fields. RPP has the potential to alleviate the pressure of China's feed imports and address issues such as low efficiency, resource wastage, and environmental harm caused by the gap between planting and feeding. In this paper, we analyze the feasibility of the RPP model, which utilizes winter fields for potato cultivation to produce animal protein. We also discuss the operational characteristics and implementation of this model. Based on the design principles of agricultural system engineering, the entire RPP system is divided into four sub-systems, including field planting management, potato storage, pig feeding with potatoes, and manure and urine treatment followed by returning nutrients to the fields. Through stepwise optimization, integration, and modeling of these sub-systems, we explore the practical implementation of the eco-circular agricultural model of RPP according to local conditions and moderate scale in southern China.