A light-guide module is used for guiding the incident light to a process device. The light-guide module includes an entrance and a plurality of reflected mirrors. The entrance is provided for entering the signal light. The reflected mirrors are arranged as a predetermined light route for guiding out the signal light. One of the reflected mirrors includes a light shielding structure for preventing the noise reflecting from the reflected mirror so as to prevent the noise light from entering the image sensing device and to prevent the image sensing device to process the noise.