Optical network unit and anomaly detection and power monitoring method thereof

The invention discloses an optical network unit, which comprises an optical transmitter, an optical detector and a signal measurement module. The optical transmitter transmits light signals to an optical line apparatus of a passive optical network system; the optical detector is used for monitoring the transmission of the optical signals and sending out the current signals; the signal measurement module is connected with the optical detector, converts the current signals into voltage signals, filters and samples the voltage signals and generates sampled signals; and the voltages of the sampled signals are averaged to obtain the average output power of the optical transmitter. When the packet uploaded by the optical network unit exceeds the time interval of the allocated timeslot, the sampled signals exceed the threshold at multiple continuous points, and the optical transmitter is shut off. The invention also discloses an anomaly detection and a power monitoring method of the optical network unit.