A network connection device, network system and method for avoiding duplication of proxy functions. The network connection device includes a bridge module for relaying a communication module of a first communication mode and a communication module of a second communication mode, a proxy Universal Plug and Play (UPnP) service module, connected with the bridge module, for providing a proxy function of a network device of the second communication mode, and a duplicate proxy Universal Plug and Play service module, connected with the communication module of the first communication mode and the proxy Universal Plug and Play service module, for preventing the proxy function of the network device of the second communication mode from being duplicated and activated at a plurality of bridges.