The invention discloses an EPON system, central office (CO) ends equipment and a method for realizing internal voice intercommunication. The CO ends equipment comprises a master control disc, at least one VoIP module and an ARP agent module matching with the VoIP module are arranged on the master control disc, the CO equipment, ODN and ONU consist of the EPON system, the OLT connects and manages remote OUN equipment through the ODN and controls and manages remote IAD equipment through the VoIP module and the ARP agent module, and voice intercommunication among a plurality of integrated access equipment IAP in system is realized through the ARP agent module. The equipment and method provided by the present invention realize voice intercommunication function in the EPON system by adding oneARP agent function of the VoIP disc without media agent, and solves problems of large difficulty, long exploitation period and high cost for realizing voice intercommunication in same PON system by using a media agent technology for the EPON system.