“A SUB FIELD” is the English abbreviation of “One Field Eco-Chain” (ASF), which aims to efficiently reverse the global trend of idle farmland by utilizing the transfer of idle rural land as a foundation, in order to maximize the value of such land. It is a new intelligent green economic ecosystem that combines advanced technologies such as blockchain, Internet of Things, Internet, and artificial intelligence to construct an open, transparent, efficient, collaborative, and controllable risk system. In terms of resource allocation and utilization, it is digitized, standardized, and structured to complete the digital transformation and upgrading of various industries, empowering the healthy development of the industry.