Abstract: The EMPIRE is an electromagnetic plasma simulation software developed by the United States for next-generation high-performance computing platforms, capable of conducting high-fidelity simulations of the entire process of high-power pulse generation, transmission, and interaction with materials. Interpreting the development progress of the EMPIRE has significant implications for the development of large numerical simulation software. This paper first analyzes the software architecture and mathematical physics scheme of EMPIRE. Then, its performance portability software features and the algorithmic characteristics of each submodule are discussed in detail. Finally, specific application cases are presented to demonstrate EMPIRE’s powerful computational capabilities. The insights from interpreting EMPIRE include the following points: using heterogeneous architectures is a key to deploying future exascale computing capabilities; developing flexible functional modules, conducting hierarchical modeling and computing, and finally integrating the entire physical process chain simulation can effectively utilize the device indicators for numerical evaluation; multi-team collaboration in development is the basis for enriching software functions; the credibility of software needs comprehensive verification and confirmation.