With the gradual improvement of automatic production in offshore oil and gas fields, cross-platform joint control is becoming more and more common. Choosing a safe, reliable and cost-effective data communication mode has become a key factor in the implementation process. The technical characteristics of OPC communication are analyzed through an example of OPC communication between a newly built platform and an old platform in a certain oilfield group of the South China Sea. The system configuration and software application methods of OPC communication are mainly expounded, so as to provide some reference for similar projects.