Abstract: Cyber-physical-social system（CPSS） is based on cyber-physical system（CPS）, adding social elements such as policies and behaviors, while breaking down barriers between fields and treating generalized physical systems as a whole. All related research and application are inseparable from the support of simulation tools. To this end, a unified simulation platform（SimCPSS） has been developed in the course of nearly 20 years of exploration of CPSS in energy（CPSSE）. It supports the interconnection, interaction and interoperability of heterogeneous simulation applications, and significantly reduces the difficulty in the simulation research of complex systems and improves the analysis efficiency. This paper introduces the design concept,architecture, functions and original technologies of Sim-CPSS. Through various engineering applications in the energy field, its adaptability to multiple fields, multiple scales, and multiple expressions of behavior has been verified. Sim-CPSS provides a basic tool support for CPSS.