Method, apparatus and system for terminal authentication in passive optical network

Disclosed in the embodiment of the present invention is a method for terminal authentication in a passive optical network, and the passive optical network comprises an optical line terminal and at least one optical network terminal. The optical line terminal is connected via an optical distribution network, characterized in that authentication parameters are preconfigured by the optical line terminal, and the method comprises: the optical line terminal receiving a registration request with authentication parameter transmitted by the optical network terminal, and the authentication parameters being used for marking the optical network terminals of the same type; the optical line terminal determining that the authentication parameters transmitted by the optical network terminal matches the authentication parameters preconfigured by the optical line terminal, and confirming the optical network terminal as a legal terminal. Through the technical solution described above, the optical line terminal can be plug-and-play without manual inputting authentication information during the registration and authentication of ONUs (Optical Network Unit), and the automation and flexibility of the authentication is improved.