The Application of IEC61850 in UHVDC (Ultra High Voltage Direct Current) project is an inevitable trend in future. Based on the in-depth study on standards IEC60870-5-101/103/104 and IEC61850, a detailed identity analysis of standard IEC61850 is given, a frame of the RCI (remote control interface) system based on standard IEC61850 is proposed, the mapping between standard IEC60870-5-104 and IEC61850 is described, and the software frame based on standard IEC61850 is given, an upgrade of the RCI system in UHVDC projects is achieved.