Switching equipment of the Time-Triggered Ethernet adopts central monitoring system to check the integrity of communication.But for a hierarchical TTE network with gateway, a communication integrity security mechanism on system level should be realized at the gateway.Based on general topological structure, this paper presents a gateway with communication integrity check function, combining the external redundancy physical link with the internal protocol check.A semi-physical simulation platform is constructed to verify the design mentioned.The results indicate that based on the full use of the equipment-level integrity check function, this design is compatible with both ends of the network transmission and can support system-level fault isolation effectively.