Method, device and system for service release

Embodiments in the present invention provide a method, a device and a system of service release, relating to the technical field of communication technology. The method of service release comprises: an Ethernet passive optical network DPoE system based on coaxial cable data service interface standard service release, sending a dynamic host configuration protocol (DHCP) request message carrying address information of the ONU to an Operation support system (OSS) server when an optical network unit (ONU) is online; the DPoE system receiving a DHCP response message from the OSS server carrying identification message of configuration files corresponding to the address information; the DPoE system determining whether the configuration files corresponding to the identification information is stored locally, if the answer being yes, the configuration files being sent to the ONU and realizing the service release of the ONU. The embodiments of the invention reduce data processing pressure on the OSS server.