The development direction of power systems is automation, networking and intelligence. The intranet and extranet dual network operation modes have been applied in the power system, but there are still many problems. Due to the continuous expansion of the power communication network, massive communication data is continuously generated in daily operation. At the same time, the means of attack on the power system communication network has evolved, seriously threatening the security of the power communication network. Therefore, it is necessary to further increase the research on the security and protection of power communication networks. This paper discusses the current status of China's power communication network, analyzes the main factors affecting the security of power communication networks and the security problems of power communication networks. Finally, corresponding protective measures are given to provide reference for improving the security and stability of power communication networks.