With the rapid development of our country's economy, the per capita level of material life has improved significantly, the corresponding power consumption is also growing sharply, which brings a severe test to the stable operation of power grid system. As the mainstream trend of the current power grid construction, intelligent substation gathers many advanced technologies, wherein the communication technology plays a more and more significant role in it, and how to ensure the communication network security has become the currently primary work content. Thus, this article mainly analyzes the communication security technology in the intelligent substation, objectively sets forth the structure of the intelligent substation by integrating the actual situation, puts forward a safer and more reliable technical solution according to the characteristics of IED, so as to provide more solid guarantee for the intelligent substation, make sure the data transmission is securer, and promote the healthy and sustainable development of power utility.