The invention relates to a fault section positioning method and
system of an optical
access network. The method comprises the following steps: acquiring a
network element alarm; if acquiring an ONU (
optical network unit) power-down alarm, acquiring equipment resource of the alarming ONU, detecting whether the alarming ONU is a MDU (multiple dwelling unit) according to the equipment resource, if the alarming ONU is the MDU, determining that the MDU is the power-down fault; if acquiring any one or more of a PON (
passive optical network) port R-LOS alarm, an ONU offline alarm, an ONU optical access bad
signal quality alarm and an ONU webmaster off-net alarm, acquiring valid ONU, and judging whether the acquired alarm is the power-down fault and determining the primary fault section according to the state of the valid ONU, and determining the final fault section according to the judgment result of the power-down fault and the primary fault section. Through the adoption of the method and
system provided by the invention, the fault of a passive facility of the optical
access network can be precisely monitored, the end-to-end accurate positioning of the fault of the optical
access network is really realized, and the coverage range of each of the pre-checking and pre-maintenance is effectively enlarged.