The remote desktop control software based on the RFB protocol is not available for overlay IP computers in WAN. A method based on RFB protocol is proposed to connect remote overlay IP computers. The communication handshaking and initialization protocol is newly developed and attached to standard RFB clients as well as the RFB server successfully. The application indicates that the modification method is feasible to be implemented and can play a critical role in monitoring and maintaining the distributed remote terminals which are in the overlap IP network with communication safety isolation technology.