Abstract: In order to eliminate the security risk of DCS network in Chongqing Natural Gas Purification Plant (hereinafter referred to as the purification plant), the network structure, security status and security risks of 10 sets of DCS system in the purification plant were analyzed, so as to find out the network security status and the security risks of DCS system in the purification plant. Combined with cause analysis and the requirements of relevant laws, regulations and standards, some improvement measures and configuration rectification suggestions on DCS network security in the purification plant were put forward according to the information of DCS network security products introduced by many DCS manufacturers. The research showed that there were three problems in DCS network security in the purification plant, i.e., few network security protection facilities, function failure of the existing protection facilities, and lack of DCS network security management system. It was concluded that the security risk of DCS network in the purification plant is increasing day by day, and it is necessary for the purification plant to further strengthen the DCS network security configuration and establish a DCS network security management system, so as to ensure the safe operation of DCS system.

Key words: natural gas purification plant, DCS, network security, status, cause analysis, improvement