Abstract: In the 5G public network scenario, using network slices can provide differentiated service for different vertical industry and thus improve network utilization efficiency.For vertical industry users with very demanding security requirements, the network slices of different vertical industries require strict isolation.Therefore, when it is found that the initial slice network cannot be served for the user terminal of the vertical industry, the initial slice network cannot pass the security context through the inter-slice channel, and the security context can only be routed to the target slice network through the 5G base station.This paper studies how to ensure the isolation of the security context and the business continuity of the terminal during the routing process without modifying the terminal as much as possible.

Key words: network slicing, secure isolation, 5G