Service provisioning method, device and system

Embodiments of the present invention provide a service provisioning method, device and system, which relate to the technical field of communications. The service provisioning method comprises: when an optical network unit (ONU) is online, a DPoE system in an Ethernet passive optical network that performs service provisioning based on data-over-cable service interface specifications sending, to an operation support system (OSS) server, a dynamic host configuration protocol (DHCP) request message carrying address information of the ONU; the DPoE system receiving a DHCP response message from the OSS server, the DHCP response message carrying identification information of a configuration file corresponding to the address information; the DPoE system judging whether a configuration file corresponding to the identification information is stored locally, and if yes, sending the configuration file to the ONU, thereby implementing service provisioning of the ONU. The embodiments of the present invention lower the data processing load of the OSS server.