Abstract: It is a core issue and a difficult point in the study of the ionosphere to extract the ionospheric disturbance from the background. This paper briefly reviews the progress of the spectral whitening method (SWM) in the study of ionospheric disturbances. It is shown that, compared with the traditional ionospheric disturbance extraction method, the SWM is more sensitive to identify the ionospheric disturbance responding to the geomagnetic storm. The ionospheric weather single station index Js, the global index Jp and the regional index Jr constructed by the SWM are closely correlated to the Dst value. This makes it possible to forecast Jp by the Dst; It is also shown that the SWM is also suitable for studying the weak ionospheric response during a severe geomagnetic storm. A comparison indicates that the weak response of the ionosphere under the condition of a strong geomagnetic storm does not depend on the disturbance extraction method itself, which is strongly related to the latitude, the local time and the conditions of the early geomagnetic storm. The SWM may serve as a useful tool to study the ionospheric disturbances responding to other sources during the quiet geomagnetic period.  Based on SWM, the Js Map can well reflect the spatial characteristics of the ionospheric disturbance during a typhoon process.