With the development of industrialization and urbanization, Chinese labor cost is gradually increasing, and the aging and shortage of agricultural labor force has become increasingly noticeable. As the traditional agricultural labor force withdraws from the first-line production, therefore, the needs for “machine substitute for man” is increasing too. Unmanned farm is a kind of all-weather, entire-process, whole-space unmanned production mode, which uses the new generation of information technology such as Internet of things, big data, artificial intelligence, 5G, and robot to complete farm production operations through remote automatic control of facilities, equipment, machinery or autonomous robot control. It included four parts: firstly, the concept, technical framework and three development stages of the unmanned farm were systematically introduced; secondly, four key technologies were systematically put forward: Internet of things, big data, artificial intelligence, intelligent equipment and robot, and four system components: infrastructure system, operation equipment system, measurement and control system and cloud management and control platform system, and five typical farm applications of the unmanned farm: unmanned fields, unmanned greenhouses, unmanned orchards, unmanned livestock farms and unmanned fisheries; finally, the forward of the development strategy of unmanned farm in China was suggested.