In order to achieve the fast and reliable data interaction between HVDC control and protection system and protect information substation, an Ethernet 103 dual network communication method in HVDC based on graphical programming is proposed. The method extends the serial port 103 communication defined by IEC 60870-5-103 standard, and proposes the Ethernet 103 dual network communication scheme to improve the real-time and reliability of communication. In addition, the method separates the application program from the underlying communication procedures, and uses the standard IEC 61131 graphical design language to develop a graphical programming method for the integration of highly encapsulated underlying communication processing module and user function module, the software programming is easy and efficient, system running and debugging information can be on-line monitoring. The experimental data of project such as Xilingol League-Taizhou project and Zhalute-Qingzhou project shows that the method has characteristics of high reliability, fast development progress, convenient operation and maintenance. Also it has an important application value to achieve the fast and reliable data interaction between control and protection system and protect information substation.