Intelligent substation based on information digitization, communication network, information sharing platform standards into the basic characteristics.Excellent network performance of intelligent substation advanced features is very important. Based on total unity of network packet transmission delay are analyzed, and further study the VLAN division method and the principle, through the VLAN and priority tag to reduce the network load and data transmission delay. Finally in OPNET environment to verify the failure in extreme cases, the division of VLAN scheme rationality and network time delay meet the requirements.