Digital Twin Network (DTN) emerges as a novel network paradigm that can provide a twin network that is highly consistent with the real physical network. Although digital twin technology has been initially practiced in computer network applications, there is currently a lack of research on the design and implementation of distributed digital twin network system. Through the establishment of digital twins for SDN networks and the collection of data from physical networks, this paper designs and implements a distributed digital twin network system based on OMNeT++. The proposed system can achieve simulation, verification, optimization, and control of the physical network, providing substantial support for network operations and accelerating network innovation.