Registration activation method and system for optical network unit

The invention discloses a registration activation method and system for an optical network unit (ONU). The method comprises the following steps: the ONU receives a registration request from an optical line terminal (OLT); the ONU transmits registration information to the OLT according to the type of the stored registration information of the ONU; and the OLT makes legal judgment on the ONU according to legal ONU registration information stored by the OLT and the received registration information, and then the registration activation treatment on the ONU is carried out according to the judgment result. In the invention, the user experience is improved and the operating cost of an operator is reduced.