Disclosed is a wavelength-division multiplexing-passive optical network having a central office including a plurality of first working and protection transmit/receive modules, working and protection optical transmitters, and a plurality of first optical switches, the first working and protection transmit/receive modules generating downstream optical signals and detecting upstream optical signals having corresponding wavelengths, the working and protection optical transmitters generating broadcasting optical signals, the first optical switches performing a switching operation when faults occur, a plurality of subscriber units for receiving broadcasting optical signals and downstream optical signals having corresponding wavelengths and generating upstream optical signals, the subscriber units including second optical switches, a remote node including working and protection optical splitters for dividing intensity of the broadcasting optical signals, the remote node being positioned between the subscriber units and the central office, working and protection main optical fibers for linking the central office with the remote node; and a plurality of working and protection branch optical fibers for linking the remote node with the subscriber units, respectively.