Smart substation is the key parts of smart grid and the network of process layer is an important foundation for smart substation which is related to the reliability and real-time of data acquisition and switch control. The type of process layer message which include generic object oriented substation event（GOOSE）， MSV（multiple sample value） and synchronization with network are generalized. The schemes of process layer network with different combination between GOOSE and MSV are discussed. The merge scheme of GOOSE， MSV and synchronization with IEEE 1588 is researched， the scheme of process layer network in a substation of 500 kV is discussed as an example. The virtual local area network（VLAN） and multicast registration protocol（GMRP） based on GARP which are used to divide the virtual network are proposed.