Disclosed are an optical signal transmission system and method, and an optical communication device. The optical signal transmission system of the present invention comprises: a PCB board, and a silicon optical chip unit, an optical transmission unit and an optical receiving unit which are arranged on the PCB board; the silicon optical chip unit is connected to the optical transmission unit via an optical fibre link on the PCB board, and the silicon optical chip unit is connected to the optical receiving unit via the optical fibre link on the PCB board; the optical receiving unit is used for receiving an optical signal transmitted from the exterior; the silicon optical chip unit is used for converting the optical signal to an electrical signal, processing the electrical signal and converting the processed electrical signal to an optical signal; and the optical transmission unit is used for transmitting the optical signal converted by the silicon optical chip unit via the optical fibre link. The optical signal transmission system of the present invention can solve the technical problem that the reliability is low when an existing optical communication device transmits a great amount of high-speed data.