Abstract: The IP address is an important basic resource for the informatization development. This paper analyzed the current situation of railway information network, the use of IP address, IPv6 address structure type, fully combined with the future development needs of railway informatization, studied and determined the applicable IPv6 address type and the required address space size of railway information network, designed the IPv6 address hierarchy and information identification rules in detail, implemented the railway information network IPv6 address planning, and put forward the allocation and use of address. The application method lays the foundation for the evolution of railway information network to IPv6.