With the emergence and development of the concept of energy Internet,the communication is playing an increasingly important role in the power system.It is necessary to study the synergy of communication system and power system.Based on the analysis of the demand of energy Internet communication,the general framework and key technologies of the simulation platform of power grid and communication network are put forward.The co-simulation platform of power grid and communication network is designed by using Matlab and OPNET to study the influence of communication on the operation of power system.Finally,a simulation example that distributed powers in energy Internet participate in the frequency modulation of power system is given to demonstrate the feasibility and effectiveness of the co-simulation platform.