The invention provides a WSS channel attenuation control method and device, a storage medium and a processor. The method comprises the following steps: for each WSS module in a multi-stage wavelengthselective switch (WSS) system, inputting white noise into a channel of the WSS module, and adjusting attenuation parameters of all fragments of the channel according to a predetermined rule, so that the flatness of an output spectrum of the white noise is smaller than a first threshold value; averaging the adjusted attenuation parameters of the corresponding fragments of the plurality of WSS modules; and controlling the WSS channel attenuation amount of each WSS module in the WSS system according to the obtained average value. The problems that in the related technology, due to the fact that multi-stage WSS can generate filtering damage to the optical signal, the performance of the receiver is degraded after the filtered optical signal enters the receiver and the like are solved, the filtering damage generated when the optical signal passes through the multi-stage WSS is effectively reduced, and meanwhile, the performance of the receiver is also improved.