Abstract: The ESD system applied at natural gas transmission stations is an important part of the SIS protective layer, and it is mainly used to reduce the risk when the process is out of control. The ESD system used at the stations of PetroChina West-East Gas Pipeline Company suffers some hidden troubles, such as the failure of the ESD button circuit and the grounding of the system, which may lead to the out of control of the process and affect the safety and availability of the system. In this paper, PetroChina West-East Gas Pipeline Company's all ESD false triggering events in recent ten years were analyzed, and different types of ESD button circuits and the features of the matched digital input cards were compared. And accordingly, the most reasonable improvement measures were selected and the effective recommendations were proposed, so that the equipment achieves the best safety and availability and the frequency of ESD false triggering events is reduced. The research results can provide the reference and guidance for the operation maintenance, reconstruction and upgrading of ESD system at gas transmission stations.