Abstract: The integrated development of transportation system and energy system is one of the effective ways to achieve the goals of "carbon peak" and "carbon neutral". On the basis of existing research, relevant policies and future development trends, an integrated energy and transportation system (IETS) development framework, which consists of regional, urban and terminal layers was proposed. Then, the system composition, development mode and application value of each layer of the IETS were introduced in detail. In addition, considering that the integration of energy system and transportation system was still in the early stage of development, this paper focused on the theory of IETS operation and then summarized the current research status of three key operation techniques: vehicle arrangement-oriented analysis, traffic flow-oriented analysis, and multi-system optimization solving. Finally, application scenarios and future research directions of the three technologies in IETS were analyzed.