To improve the time synchronization protocol in automotive environment, this paper proposes optimization methods including master clock arbitration, startup timing, redundant path selection and fault recovery mechanism. The feasibility and effectiveness of these methods are tested on the real network. Without reducing synchronization accuracy, the optimization methods keep the new time synchronization process in a predictable state. Synchronous clock is faulttolerant to node and link fault. Moreover, the faulttolerant mechanism is proposed when synchronization fails completely, so as to avoid the impact of synchronous failure on normal driving.