The invention discloses an EPON link data collecting and analyzing device which comprises a link beam split module, a protocol analyzing module and a data analyzing module. The link beam split module is used for receiving EPON light signals and separating uplink EPON light signals and downlink EPON light signals. The protocol analyzing module is connected with the link beam split module and is used for reverting the received uplink EPON light signals and the received downlink EPON light signals into Ethernet data frame signals which are transmitted to the data analyzing module. The data analyzing module is connected with the protocol analyzing module and is used for collecting and analyzing data from the received Ethernet data frame signals. The invention further provides an EPON link data collecting and analyzing method. EPON data collecting and protocol analyzing are achieved, non-object data and useless data filtering is achieved, decryption on collected EPON data is achieved, restoring of the network record of a target user is achieved, user normal use daily service is not affected, and even if equipment power failure happens, all users can work normally.