The network communication performance of process layer plays a decisive role in the safe and stable operation of intelligent substation. However, the opaque and invisual features of the Ethernet network makes the network communication of process layer uncontrollable, which hinders the development of the intelligent substation. Starting from the message characteristic of process layer network, this paper analyzes the message characteristics of a typical intelligent substation i.e. Qin Yun intelligent substation, then studies the communication characteristics of the process layer, points out the deficiency of the communication configuration, and proposes some improvement methods. It can make the process layer network transparent and controllable to some extent and has a certain exploratory significance on the construction of the intelligent substation.