With the continuous growth of air transport and facing energy depletion and environmental crisis, a grand challenge has been posed to the sustainable development of the current air transport system. Based on new energy and materials, big data, artificial intelligence and broadband communication technologies, it has become a global consensus and risen to the level of national strategy to build a smart air transport system (SCATS) that is safe, efficient, green, smart and convenient. This paper focuses on reviewing the background of the develop? ment of the SCATS, listing related environmental policies, analyzing its connotation and characteristics, and putting forward the overall architecture and key technologies of the system. Besides, the latest development of SCATS is summarized and relevant suggestions of the SCATS are proposed.