With the widespread popularization of electric vehicles (EVs) and the increasing level of electrification in transportation, there is a growing trend of deep coupling between the distribution grid and the transportation network. Achieving efficient interaction between EVs and the power-transportation coupled network can effectively enhance the stability of grid operation and alleviate congestion in the transportation network, thus becoming a research hotspot in the fields of power systems and EVs. This paper provides a comprehensive introduction to the basic concept of the power-transportation coupled network and delves into three key areas: modeling and state prediction of the power-transportation coupled system, EV charging station planning under the coupling of the two networks, and optimal dispatch and control under the coupling of the two networks. Additionally, it analyzes the status of the development of its standard system and offers forward-looking prospects for its future direction.