The present invention relates to a multi-computers network sharing system having plug-and-play interfaces, comprising: an ethernet physical unit, a media accessing and controlling unit, a flow control unit, a plug-and-play interface transforming module, and a plurality of plug-and-play interfaces. In the multi-computers network sharing system of the present invention, when one of the external electronic devices is connected to any one of the plug-and-play interfaces, the flow control unit transmits the ethernet signal accessed by the first media accessing and controlling unit to the plug-and-play interface transforming module, therefore the plug-and-play interface transforming module transforms the ethernet signal to a plug-and-play interface signal and next transmits the plug-and-play interface signal to the electronic device connected with the plug-and-play interface, such that the electronic device can connect to the Internet without using any network cables or wi-fi devices.