Regional integrated energy system is a typical multi energy coupling and multi time scale complex system. How to carry out co-simulation of multi energy steady-state power flow of cooling, heating and power and output of various equipment is one of the difficulties at this stage. Firstly, characteristics of regional integrated energy system are analyzed, and then based on interface standard of FMI, the basis for multi time scale coordination and multi type energy data interaction of multi energy coupling system is provided. Then, distributed structure design framework is adopted to carry out parallel calculation in different simulation subsystems through inter process communication, and the simulation solution process is divided into topology analysis, script generation, FMU package and simulation execution. Finally, feasibility and rationality of the proposed technical simulation scheme in the application of regional integrated energy system simulation are verified through the simulation of an industrial park in Nanjing, which meets the actual needs of steady-state simulation. It has a certain practical engineering application value.