A management method of an optical fiber network system is disclosed. The optical fiber network system includes at least one user apparatus and an optical network unit (ONU), and the ONU is connected with the user apparatus. The management method includes the steps of: adopting at least one information string, which is set by an ONU management and control interface (OMCI), by the optical network unit; packing the information string into a management packet; and transmitting the management packet to the user apparatus by the optical network unit according to an Ethernet protocol.