Abstract: When the shutdown alarm signal is transmitted between the offshore oil and gas field platforms by means of public protocol conversion, especially in the case of satellite links, there are many signal transmission links and poor reliability. In order to improve the reliability, a project in the East China Sea adopts the extension method of safety net. When dangerous situations such as oil and gas leakage and fire and explosion occur, platforms with upstream and downstream logistics relations are closed down. Extend the safety net, connect the security system between each platform, reduce the intermediate links, so that each platform has the same level of security between the production operations.The reliability has been effectively improved. By extending the safety net through satellite links, we can turn them off in time to ensure that the hazard does not spread when dangerous situations occur. Combined with the requirement of limiting development costs, the conditions for implementing the security shutdown chain through satellite links are also increasing. The example proves that the technology based on satellite link extended safety net has high reliability and is worthy of popularization and application.