Time Triggered (TT) network can ensure the reliability and real-time performance of data transmission in safety-critical systems.The basic principles of monitoring and fault-tolerant mechanisms of TT network are analyzed.The monitoring mechanisms based on time windowsemantics and data flow are designed respectivelyand the synchronous fault-tolerant mechanism based on redundant resources and the high-integrity fault-tolerant mechanism based on COM/MON architecture are designed.A verification environment for these monitoring and fault-tolerant mechanisms is builtand relevant verification tests are conducted.The results show that the analysis and design of monitoring and fault-tolerant mechanisms can enhance the safety level of TT network.