Abstract: Time-triggered Ethernet (TTE) guarantees real-time transmission of communication data through precise time scheduling, and stands out in many fields of data transmission with high real-time requirements. Analyze the TTE synchronous characteristic we can compensate the local clock of synchronous main node through the least square clock compensation algorithm in the project and improve determinacy and real-time nature. However, the local clock of the synchronous master node is vulnerable to the influence of the external environment to generate outliers, which affects the applicability of the least squares clock compensation algorithm. Therefore, this paper proposes a clock compensation algorithm with outlier pre-elimination to improve the real-time performance of the system. That is, firstly, the Least Square criterion (Pauta criterion) is used to pre-eliminate the least-squares-sensitivity local clock outliers, then the local clock compensation value is estimated by least-squares method, and finally the local clock is processed according to the estimated clock compensation value. Simulation results show that the proposed method solves the problem of local outliers occurring at the synchronous master node in the TTE clock compensation. The results show that the clock synchronization accuracy of the proposed algorithm can reach 10^-6 seconds when the outlier ratio is less than 10%. It is much higher than the 10^-3 second-level accuracy of the least squares clock compensation algorithm with no outlier pre-elimination.