Since 2019, the National Natural Science Foundation of China (NSFC) has been actively promoting scientific fund reform in the new era. In light of this, NSFC’s Department of Atmospheric Sciences took the lead in carrying out the reform of project review classification to help optimize the layout of discipline funding and formed the new application code system through strategic research and discussion. The new system is made up of 15 secondary application codes divided into three categories: sub-disciplines, supporting technologies, and development fields. As a result, the research directions and keywords of each secondary application code were also redesigned, implemented, and continuously optimized. The secondary application code “D0504 Atmospheric Dynamics” retains its name unchanged in this reform, but its connotation and scope have been slightly widened. One notable development is that the boundary between traditionally accepted “dynamics” and “physical processes” is becoming fuzzy and changing, which leads to a widening of the connotation of atmospheric dynamics to many fields previously considered “physical processes”. Meanwhile, the scope of atmospheric dynamics is also expanding from simply investigating the dynamics of the atmosphere to examining the dynamics of the atmosphere’s interactions with other spheres. Its research methods are also changing, from experimental research, theoretical analysis, and numerical simulations with simplified models to experimental research, fact analysis, theoretical analysis, and numerical simulations with hierarchical models. In order to serve the application and review of proposals and promote the development of the discipline, this paper interprets the essence, scope, and logic of the research directions and keywords of the secondary application code “D0504 Atmospheric Dynamics”. It also briefly analyzes the application data under the secondary application code to demonstrate how the keywords were used during 2020–2022.