In recent years, two-dimensional (2D) materials such as graphene, MXene, MOF, and black phosphorus have been widely used in various fields such as energy storage, biosensing, and biomedicine due to their significant specific surface area and rich void structure. In recent years, the number of literatures on the application of 2D materials in electrochemistry has gradually increased. To help people better understand 2D materials and facilitate the subsequent development of 2D materials, this paper focuses on several mainstream 2D materials. It mainly includes the following three aspects: synthesis and energy storage mechanism, preparation scheme, and the role played in each electrochemical device. In this paper, the synthesis mechanism of most 2D transition metal compounds, carbon materials, and organic materials is described by focusing on the 2D structure of transition metal compounds, carbon materials, and organic materials, including two processes of high-dimensional structure stripping and low-dimensional structure self-assembly. The energy storage mechanism of most 2D materials was revealed through the mechanism of ionic (in) sertion reaction and redox. The synthesis methods of physical, chemical, and physicochemical combination of most 2D materials and the advantages and disadvantages of different methods are summarized. The great effects of 2D materials on electrode materials, electrolyte, and diaphragm are summarized in terms of operating voltage window, rate capacity, dynamic behavior, specific discharge capacity, cycle stability, and so on. Finally, we also introduce the current challenges and future research directions of 2D materials, and hope to see the figure of 2D materials in more fields.