The invention relates to an optical fiber communication system which can detect a plurality of mining conveyor belts, comprising an underground control module, a no-source optical distributing network, a surface main controller and a control computer. The underground control module firstly multiplexes signals collected by a conveying belt sensor into high-speed optical signals and then sends signals to the surface main controller, and the surface main controller de-multiplexes signals into original sensor signals and then sends the signals to a signal processor. The surface main controller controls the sending of a plurality of underground control modules through lower data chancels to lead the plurality of underground control modules to share the optical fiber link. The optical fiber communication system makes use of the no-source optical fiber network to transmit the sensed signals of the plurality of conveying belts, thus displacing the underground signal processing system and highly enhancing the anti-interference capability and reliability of the system.