This paper studies an integrated power system simulation platform based on PSD-BPA and PSS®E two kinds of simulation tools, in response to the increasing scale of power grids and the increasing complexity of structures, the large-scale application of power electronic equipment, and the continuous in-depth transformation of power market transactions to the challenge of power system simulation and calculation. The integrated simulation platform mainly includes data management and integrated simulation. It establishes the integrated simulation system structure and functional structure with integrated data sharing as the goal, and describes the platform workflow, implementation scheme, and features. Through the PSS®E user-defined interface, the dynamic model conversion and generalized modeling of conventional equipment in the power system are realized, a unified system simulation model of the integrated simulation platform is formed, and integrated simulation is realized. Combined with the unified model data of a certain regional power grid maintained by the integrated simulation platform, the advantages of the two software’s in their respective data foundations and custom models are exploited, which verifies the availability and flexibility of the integrated simulation platform for custom modeling and simulation of new types of equipment.