The invention relates to the technical field of optical fiber transmission, in particular to a method for improving optical fiber transmission reliability. The method comprises the following steps of step S101 optical fiber communication connection; step S102 secure communication authentication; step S103 secure communication determination; and step S104 secure optical fiber communication. The invention further discloses a device for improving optical fiber transmission reliability. The device comprises a power distribution terminal arranged on an optical fiber, wherein the power distribution terminal is in communication connection with a power communication network through an optical fiber; the power communication network is in communication connection with a background server; and a secure authentication unit is arranged between the background server and the power distribution terminal. By adopting the method and the structure, the secure authentication information sent by a power distribution module of the optical fiber is authenticated through a secure authentication module, and after the secure authentication module determines the secure authentication information, the background server sends a control signal to the power communication network, and reliability transmission of the optical fiber is realized through the power communication network.