With the rapid development of energy Internet, more and more distributed energy systems are accessed. The demand for network and information security of energy information is increasingly urgent. Theoretically, quantum secure communication can achieve unconditional and absolute security in information communication. However, its application in power grid is still in the stage of exploring. This paper focuses on the performance evaluation of power quantum secure communication in the global energy Internet field. Firstly, considering the diversity of the grid business scenario and transmission loss, the system architecture diagram of power quantum secure communication is proposed. Then, through the simulation of the power communication transmission environment and actual business scenario, indicators that quantum channel and data exchange channel of power quantum secure communication system are evaluated in six aspects (e.g. distance loss, pendulum loss and connection loss). Finally, the feasibility and security of quantum secure communication technology in power communication field are verified by simulation experiments, and the development of energy Internet can be effectively assured.