A rogue ONU detection and recovery method in a PON network includes steps of: monitoring upstream signals transmitted from a plurality of ONUs to an OLT to acquire LOS signal information and FEC error information; sensing an operation of the rogue ONU in the PON network on the basis of the LOS signal information and the FEC error information; and deactivating at least one of the plurality of ONUs and recovering the rogue ONU to a normal ONU according to whether or not the operation of the rogue ONU is released.