A method of detecting wavelength label conflict, comprising: performing spectrum analysis on received wavelength label signals; determining that wavelength labels conflict when judging that at least one of the following two conditions is met: there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading a wavelength label frequency, a maximum difference value between amplitude values of N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, none of the amplitude values thereof belongs to a reference amplitude value range, and both M and N are integers greater than 1; there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading the wavelength label frequency, the maximum difference value between the amplitude values of the N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, a maximum difference value of phase values thereof is smaller than a preset phase threshold value, none of the phase values thereof belongs to a reference phase range, and both M and N are integers greater than 1. performing spectrum analysis on received wavelength label signals; determining that wavelength labels conflict when judging that at least one of the following two conditions is met: there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading a wavelength label frequency, a maximum difference value between amplitude values of N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, none of the amplitude values thereof belongs to a reference amplitude value range, and both M and N are integers greater than 1; there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading the wavelength label frequency, the maximum difference value between the amplitude values of the N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, a maximum difference value of phase values thereof is smaller than a preset phase threshold value, none of the phase values thereof belongs to a reference phase range, and both M and N are integers greater than 1. there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading a wavelength label frequency, a maximum difference value between amplitude values of N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, none of the amplitude values thereof belongs to a reference amplitude value range, and both M and N are integers greater than 1; there are N successive time windows in M time windows whose corresponding wavelength label signals are wavelength label signals transmitted by loading the wavelength label frequency, the maximum difference value between the amplitude values of the N wavelength label signals corresponding to the N time windows is smaller than a preset amplitude threshold value, a maximum difference value of phase values thereof is smaller than a preset phase threshold value, none of the phase values thereof belongs to a reference phase range, and both M and N are integers greater than 1.