A multimedia signal transmission device comprising: a clock signal detector, a first microcontroller unit, a first photoelectric module, a second photoelectric module and a second microcontroller unit, wherein the clock signal detector is coupled to a signal source, for detecting a clock signal inputted from the signal source and generating a clock index which contains information specifying a frequency of the clock signal; wherein the first microcontroller unit is coupled to the signal source for receiving the clock index generated by the clock signal detector and is for receiving multiple differential signals inputted from the signal source and combining the multiple differential signals and the clock index into multiple packets; wherein the first photoelectric module is coupled to the first microcontroller unit and the signal source for receiving multiple minimized differential data signals inputted from the signal source and the multiple packets transmitted from the first microcontroller unit and converting them to optical signals; wherein the second photoelectric module is coupled to the first photoelectric module for receiving the optical signals from the first photoelectric module and converting them to the multiple minimized differential data signals and the multiple packets; and wherein the second microcontroller unit is coupled to the second photoelectric module for generating the clock index and the multiple differential signals from the multiple packets; characterized in that the multimedia signal transmission device further comprises: a clock data recovery circuit, coupled to the second microcontroller unit and the second photoelectric module, for receiving one of the multiple minimized differential data signals inputted from the second photoelectric module and receiving the clock index from the second microcontroller unit, and for recovering the clock signal which has the frequency specified in the clock index and is synchronized to the one of the multiple minimized differential data signals. a clock signal detector, a first microcontroller unit, a first photoelectric module, a second photoelectric module and a second microcontroller unit, wherein the clock signal detector is coupled to a signal source, for detecting a clock signal inputted from the signal source and generating a clock index which contains information specifying a frequency of the clock signal; wherein the first microcontroller unit is coupled to the signal source for receiving the clock index generated by the clock signal detector and is for receiving multiple differential signals inputted from the signal source and combining the multiple differential signals and the clock index into multiple packets; wherein the first photoelectric module is coupled to the first microcontroller unit and the signal source for receiving multiple minimized differential data signals inputted from the signal source and the multiple packets transmitted from the first microcontroller unit and converting them to optical signals; wherein the second photoelectric module is coupled to the first photoelectric module for receiving the optical signals from the first photoelectric module and converting them to the multiple minimized differential data signals and the multiple packets; and wherein the second microcontroller unit is coupled to the second photoelectric module for generating the clock index and the multiple differential signals from the multiple packets; characterized in that the multimedia signal transmission device further comprises: a clock data recovery circuit, coupled to the second microcontroller unit and the second photoelectric module, for receiving one of the multiple minimized differential data signals inputted from the second photoelectric module and receiving the clock index from the second microcontroller unit, and for recovering the clock signal which has the frequency specified in the clock index and is synchronized to the one of the multiple minimized differential data signals.