The invention provides a user access device and a wireless LAN system including the same. The device comprises an antenna, and further comprises: a mainframe terminal device, and an equipment terminal device connected with the mainframe terminal device through connection devices disposed at both sides of a twisted pair. The mainframe terminal device comprises: an interface device for connecting to the terminal, and a first transfer circuit for two-way transferring the terminal signal and the twisted pair signal. The equipment terminal device comprises: a connector for connecting the antenna, and a second transfer circuit for two-way transferring the radio frequency signal and the twisted pair signal, wherein the twisted pair transfers a digital baseband signal, the connector of the equipment terminal device is connected to the antenna through a radio frequency cable. The user access device has a long distance between the antenna and the user mainframe, so that the sender and the receiver for the wireless signal can be arranged indoor or outdoor with a little shield or a few reflecting objects.