A transmission device having optical fiber high definition digital audio-video data interface (HDMI/DVI/UDI), in which optical fiber is utilized as the physical connection for the logical channels of the transmission device, and is used to carry images, voices and auxiliary data of the logic channels. For the half-duplex transmission mode utilized by the display data channel, the reverse unit, the serial unit, and the multi-serial unit are properly arranged, thus fulfilling the DC balance requirement of optical fiber transmission, and resolving the lower tolerance rate shortcomings of the I2C bus specification of display data channel (DDC) and the customer electronics control (CEC) channel.