A method for operating a photoelectric switch, said photoelectric switch comprising a light transmitter unit comprising a plurality of light transmitters (10-1, 10-2,...,10-N), a light receiver unit comprising a plurality of optical fiber receivers (20-1, 20-2,..., 20-N) arranged in one-to-one correspondence with said plurality of light transmitters (10-1, 10-2,...,10-N), a photoelectric conversion unit connected to said optical fiber receivers (20-1, 20-2,..., 20-N), and a control and processing unit connected to both said light transmitter unit and said photoelectric conversion unit, said method comprises the steps of: emitting, by the plurality of light transmitters (10-1, 10-2,..., 10-N), a plurality of light signals; receiving, by the plurality of optical fiber receivers (20-1, 20-2,..., 20-N), said plurality of light signals and to merge said received plurality of light signals, wherein an object detection area is defined between said plurality of light transmitters and said plurality of optical fiber receivers; performing, by the photoelectric conversion unit, photoelectric conversions on said merged light signals outputted by said optical fiber receivers so as to generate an electric signal; and controlling and processing, by a control and processing unit, said light signals and/or said electric signal; wherein, the step of controlling and processing further comprises: amplifying, by an amplification circuit, said electric signal outputted by said photoelectric conversion unit, to form a one and an another amplified electrical signals; performing an analog-digital conversion and processing for the one amplified electrical signal, to obtain a digital value; and performing a demodulation processing on the another amplified electric signal, to obtain a demodulated signal value. emitting, by the plurality of light transmitters (10-1, 10-2,..., 10-N), a plurality of light signals; receiving, by the plurality of optical fiber receivers (20-1, 20-2,..., 20-N), said plurality of light signals and to merge said received plurality of light signals, wherein an object detection area is defined between said plurality of light transmitters and said plurality of optical fiber receivers; performing, by the photoelectric conversion unit, photoelectric conversions on said merged light signals outputted by said optical fiber receivers so as to generate an electric signal; and controlling and processing, by a control and processing unit, said light signals and/or said electric signal; wherein, the step of controlling and processing further comprises: amplifying, by an amplification circuit, said electric signal outputted by said photoelectric conversion unit, to form a one and an another amplified electrical signals; performing an analog-digital conversion and processing for the one amplified electrical signal, to obtain a digital value; and performing a demodulation processing on the another amplified electric signal, to obtain a demodulated signal value. amplifying, by an amplification circuit, said electric signal outputted by said photoelectric conversion unit, to form a one and an another amplified electrical signals; performing an analog-digital conversion and processing for the one amplified electrical signal, to obtain a digital value; and performing a demodulation processing on the another amplified electric signal, to obtain a demodulated signal value.