Multipath interference detection method, receiving device and system

The embodiment of the invention provides a multipath interference detection method, receiving equipment and a system, which are applied to the field of optical fiber communication and can realize accurate detection of multipath interference under the condition that service transmission does not need to be interrupted. The method comprises: a light receiving device performs Fourier transform on a to-be-measured electric signal to obtain a target corresponding relationship of the to-be-measured electric signal, wherein the target corresponding relationship indicates a corresponding relationship between a frequency value of the to-be-measured electric signal and a target parameter; the light receiving device obtains K target parameters corresponding to K frequency values according to the target corresponding relation, the absolute value of the difference value of any two target parameters in the K target parameters is larger than or equal to a preset value, and K is a positive integer larger than or equal to 2;